Leetcode C Programming

You may assume that the maximum length of S is 1000, and there exists one unique longest palindromic substring. In other words, if given the word PROGRAMMING and asked to scramble it into 3 rows of zigzag letters, our program should return the string PRIRGAMNOMG. Fill in the blank exercises are designed for true beginners, where a large portion of the code is already provided!. A comment is used to display additional information about the program. C/C++ Coding Exercise - Evaluate Reverse Polish Notation - Leetcode Online Judge - Using Stack April 8, 2014 No Comments algorithms , c / c++ , code , code library , compiler , data structure , implementation , leetcode online judge , math , programming languages. C/C++ Coding Exercise - Jump Game - Linear Solution (Leetcode Online Judge) November 28, 2014 No Comments c / c++ , code , greedy algorithm , leetcode online judge , programming languages , simulation. This project aims at solving LeetCode algorithm problems with pure C Language using as little library functions as I can, which means except memory management functions and few string functions I will implement everything I need such as trees, stacks, queues and hash tables. C programming was designed and written by a man named Dennis Ritchie. You should know when it is better to use list or dictionar. Tags | clueless coding Code snippets and programming tips. GeeksforGeeks: Dynamic Programming | Set 28 (Minimum insertions to form a palindrome) Minimum insertions to form a palindrome. Featured on Meta The Q1 2020 Community Roadmap is on the Blog Leetcode container with most water. Array 229 Dynamic Programming 188 Math 171 String 162 Tree 130 Hash Table 123 Depth-first Search 120 Binary Search 84 Greedy 73 Breadth-first Search 66 Two Pointers 60 Stack 54 Backtracking 53 Design 46 Sort 45 Bit Manipulation 44 Graph 40 Linked List 38 Heap 34. The testcase in question is the last str initialized in the main method. LeetCode has a problem to reverse digits of an integer number without using any library method like reverse() method of StringBuffer. Given a binary …. This explains why the example program below prints just one line. LeetCode Problems' Solutions. C/C++ Coding Exercise - Unique Paths II - Dynamic Programming with Obstacles - Leetcode Online Judge - DP with Constraints. What is a Narcissistic Number?. I've decided to separate the problem into two parts because the solution using maths knowledge recalled me the happy time when I studied maths in high school. We often need to maintain our portfolio where we keep our projects, competitive programming codes and blog links. The same repeated number may be chosen from C unlimited number of times. Problem: There are N children standing in a line. org or mail your article to [email protected] The python code is as follows. Another representation is to use ax+by=c, but personally I do not like it since it requires gcd and more values to hash. Whether or not you think it's a practical kind of programming, you're free to argue (though we probably disagree). Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory. Contents 1Rotate Array in Java 7 2Evaluate Reverse Polish Notation 9 3Solution of Longest Palindromic Substring in Java 11. Critical tools united for a better developer workflow. All the source files are numbered according to problem no. The problem can be solved with naive brute force. Array 228 Dynamic Programming 186 Math 171 String 159 Tree 129 Hash Table 123 Depth-first Search 117 Binary Search 84 Greedy 73 Breadth-first Search 66 Two Pointers 60 Stack 54 Backtracking 53 Design 46 Bit Manipulation 44 Sort 44 Graph 40 Linked List 38 Heap 34. The Dynamic Programming DP is one of the most-used approach to solve problems that satisfy…. com/discuss/20619/c- I came up with a solution similar to. C programming language is a base to learn different programming language. In our program, we check if a string is a subsequence of another string. 1) Iterate through all characters of given string, do following a) If current character is a space, then move all subsequent characters one position back and decrease length of the result string. The repetition of two trees means that they have the same structure and the same node value. Posts about leetcode written by 13abyknight. LeetCode - Decode Ways (Java) digits, determine the total number of ways to decode it. The tutorial provides a step-by-step demonstration on how to solve coding problems. You examine the typed characters of the keyboard. This is how Topcoder was born: competitive programming for fun (and bragging rights). I have these values starting as Integer. C was adopted as a system development language because it produces code that runs nearly as fast as the code written in assembly language. It can be purchased from https://leetcode. Compare Version Numbers: C++ Solution. It's good that within limits the proposed code works. 思路: use map1: map to store use map2: degree to store //based on loop not the final one Iterate each two adjacent string, to fill map and update degree use a queue to do BFS. Java code is formatted by Language Support for Java. One problem can have many tags; Discussion: for each problem, there is a forum thread where people can discuss/share solutions. LeetCode Solutions Getting Started. (C doesn't provide an array type with an explicit length. Programming for Everyone by University of Michigan. At first, you should understand the problem correctly: e ach step you may move to adjacent numbers on the row below. The original author has not been found yet background System administrators often need SSH or telent to log in to the Linux server remotely, and often run tasks that take a long time to complete, such as system […]. I think the biggest selling point for premium users is the extra problems. Play Leetcode with different programming language. C语言会的多些,java用的不熟练,c++只知道点皮毛。 看了LeetCode上面第一题用到Hash,像java实现HashMap很方便,而C实现map没那么容易(我不会)。 我就是想知道做LeetCode上面的题是想法更重要吗?什么语言实现都无所谓? 以前做过一点acm,那种做题一般就是固定一. Gray Code The gray code is a binary numeral system where two successive values differ in only one bit. Simply, for target is zero, we aim to find a pair (c ,d) of which the sum equals to the negative sum of (a, b). In order to use backtracking, you need to know how gray code works or how can it be built with backtracking. Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack. Given a string, your task is to count how many palindromic substrings in this string. Make yourself familiar with data structures [3]. The searching for the first capital in word should not be in the backtracking procedure, otherwise, it's difficult to implement it. Analysis: My goal is to be able to do this in $ O(n \log n) $ time. Longest Palindromic Substring(Strat Leetcode - 328. Learn How To Find if a Number is a Narcissistic Number or not in C Programming Language. Therefore, the pair is unique to a line, which can be used as the hash key. Given a non-negative integer num, repeatedly add all its digits until the result has only one digit. C programming is a language developed by AT & T’s Bell Laboratories of USA in 1972. An anagram is a type of word play, the result of rearranging the letters of a word or phrase to produce a new word or phrase, using all the original letters exactly once; for example, Torchwood can be rearranged into Doctor Who. If someone can help me out here that would be amazing, I have passed 984/987 testcases Thanks! · ·. An island is surrounded by water and is formed by connecting adjacent lands horizontally or vertically. Solve LeetCode problems in VS Code. At first, you should understand the problem correctly: e ach step you may move to adjacent numbers on the row below. The repetition of two trees means that they have the same structure and the same node value. Given an array of integers, find two numbers such that they add up to a specific target number. config/leetcode folder. Really really really recommend EPI over CTCI but that is personal preference. Leetcode – Word Break (Java) Given a string s and a dictionary of words dict, determine if s can be segmented into a space-separated sequence of one or more dictionary words. I am having trouble understanding one of a Leetcode Problem. One problem can have many tags; Discussion: for each problem, there is a forum thread where people can discuss/share solutions. In computer programming, iterators are objects that enable a program mer to traverse containers, particularly lists. Implementation [-] Python code accepted by LeetCode OJ. Given a non-negative integer n. C programming language is a base to learn different programming language. C++ Programming Language C++ is a general purpose programming language and widely used now a days for competitive programming. Visit Stack Exchange. I was working on the “Largest Number” problem in LeetCode several days ago, and my first Java version didn’t pass the time limit. Markdown on GitHub, beautiful docs on GitBook, always in sync. No, they're programming problems. Not a clue why. C has survived for more than 3 decades. Modified Kaprekar Numbers Hacker Rank Problem Solu LeetCode - Two Sum Problem. One problem can have many tags; Discussion: for each problem, there is a forum thread where people can discuss/share solutions. Contents 1Rotate Array in Java 7 2Evaluate Reverse Polish Notation 9 3Solution of Longest Palindromic Substring in Java 11 4Solution Word Break 15 5Word Break II 18 6Word Ladder 20 7Median of Two Sorted Arrays Java 23 8Regular Expression Matching in Java 25. Leetcode 652: find duplicate subtrees Title: Given a binary tree, all the repeated subtrees are returned. A hub of software engineering career tips, code snippets, interview preparation, and programming in general. Simply, for target is zero, we aim to find a pair (c ,d) of which the sum equals to the negative sum of (a, b). Analysis: (Dynamic programming)To prevent repeating works, the comparison results should be saved somewhere for future use. In other words, if given the word PROGRAMMING and asked to scramble it into 3 rows of zigzag letters, our program should return the string PRIRGAMNOMG. C and C++ Programming Practice Problems Many of these problems will also make for excellent C++ job interview preparation. Each child is assigned a rating value. C was initially used for system development work, particularly the programs that make-up the operating system. Solution 1: brute force way to do it would be scan each character in S, and compare its left and right, and until its left and right are not equal. That's my code and I don't know why it doesn't want to work. Hi I'm working on a program for class and I can't seem to figure out what I am doing wrong. Sometimes, when typing a character c, the key might get long pressed, and the character will be typed 1 or more times. Welcome to the learn-c. Pure C solution for LeetCode. So our effort will pay on this first. 2020-03-08 by Evan, posted in leetcode. LeetCode Problems' Solutions. 000 [] 001 [a] 010 [b] 011 [ab] 100 [c] 101 [ac] 110 [bc] 111 [abc] Then the problem is pretty easy, for each number in binary format, check which bit is 1 or 0, we just add the ith number into the set if the ith bit in the number is 1. Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. LeetCode – Decode Ways (Java) This problem can be solve by using dynamic programming. How to solve rubik's cube 3×3. Contents 1Rotate Array in Java 7 2Evaluate Reverse Polish Notation 9 3Solution of Longest Palindromic Substring in Java 11. This code will close the synchronize of two kinds of input and output in C format and C++ format. 2015年初, Julia开始参与做Leetcode, 开通自己第一个博客. This program takes in two arguments – the original string and the number of rows. Leetcode: Combination Sum in C++ Given a set of candidate numbers ( C ) and a target number ( T ), find all unique combinations in C where the candidate numbers sums to T. Problem: There are N children standing in a line. I have a question though. Some of the top contributors like Stefen Pochmann(his blog), dietpepsi, j. We start to use backtracking from the second searching. A Computer Science portal for geeks. Simply, for target is zero, we aim to find a pair (c ,d) of which the sum equals to the negative sum of (a, b). Algorithm and steps to reverse a singly linked list. 7k+ stars and 2. [leetcode 1374] Generate a String With Characters That Have Odd Counts. For example, given. At the beginning when we want to recursively solve a problem on LeetCode, what do you come up in your mind? It is terminologies like Divide and Conquer ∪ Dynamic Programming ∪ Backtracking. Program for Quick Sort in C++. You will learn from the very basic but reach to a master level programmer. When in the future comparison, if we find that the comparison have been done before and we don't need to do it again and just use the results directly. it gives you more friendly look than other legacy programming platforms. A hub of software engineering career tips, code snippets, interview preparation, and programming in general. Implement strStr(). Leetcode: 3Sum Given an array S of n integers, are there elements a , b , c in S such that a + b + c = 0? Find all unique triplets in the array which gives the sum of zero. Asking for code reviews is ok as long as you follow the relevant policies. Posted by miafish in LeetCode, Stack and Queue, Dynamic programming; Greedy; Hash Table; Heap. Problem: There are N children standing in a line. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. It is similar to the problem of counting ways of climbing stairs. On leetcode it says my result should be 9, but according to the website I am outputting 10. Even though LeetCode has competitive problematic questions it mainly based on Interview Questions. Coding Style. Over 1450 questions for you to practice. To understand this example, you should have the knowledge of the following C programming topics:. That's my code and I don't know why it doesn't want to work. The Two way BFS is not improving anything here. Solve the kata with your coding style right in the browser and use test cases (TDD) to check it as you progress. Well I am still learning C++ and once I am good enough with STL I will update the repository with codes in C++ also. Wanted to give it some serious time and make a move in my career. You may assume that the maximum length of S is 1000, and there exists one unique longest palindromic substring. Sparse Matrix Multiplication. Visit Stack Exchange. The goal of the problem is to test your backtracking coding ability. I've decided to separate the problem into two parts because the solution using maths knowledge recalled me the happy time when I studied maths in high school. For example, given [3, 30, 34, 5, 9], the largest formed number is 9534330. There is no need to download anything - Just click on the chapter you wish to begin from, and follow the instructions. How to solve rubik's cube 3×3. I recommend you to learn algorithm time/space complexity[1] and Big O notation [2] concepts. A very important tool to have in our arsenal is backtracking, it is all about knowing when to stop and step back to explore other possible solutions. Leetcode: 3Sum Given an array S of n integers, are there elements a , b , c in S such that a + b + c = 0? Find all unique triplets in the array which gives the sum of zero. Like I said, I am getting a 9 on my end. Ugly numbers are positive numbers whose prime factors only include 2, 3, 5. Sometimes, when typing a character c, the key might get long pressed, and the character will be typed 1 or more times. Tag: LC assigns tags to problems based on the underlying data structure and algorithm. leetcode -h also works. We often need to maintain our portfolio where we keep our projects, competitive programming codes and blog links. set [a,b,c], write the binary numbers of length 3. C Program to Calculate Difference Between Two Time Periods In this example, you will learn to calculate the difference between two time periods using a user-defined function. GitHub is home to over 40 million developers working together to host and review code, manage projects, and build software together. Backend: Python and c++ backend for the web application of automatic detection of plagiarism. Program Talk All about programming : Java core, Tutorials, Design Patterns, Python examples and much more. Sparse Matrix Multiplication. add c to queue when its degree is 0. This is a subreddit for learning programming, not a "critique my project" or "advertise my project" subreddit. Leetcode Pattern 3 | Backtracking. This explains why the example program below prints just one line. com, you can just ignore this section. In other words, if given the word PROGRAMMING and asked to scramble it into 3 rows of zigzag letters, our program should return the string PRIRGAMNOMG. The original author has not been found yet background System administrators often need SSH or telent to log in to the Linux server remotely, and often run tasks that take a long time to complete, such as system […]. Required knowledge Basic C programming, Functions, Singly Linked List, Dynamic memory allocation Algorithm … Continue reading C program to reverse a Singly Linked List →. Online judges like Leetcode do not have API to download your submissions. C Program for Program for array rotation Write a function rotate(ar[], d, n) that rotates arr[] of size n by d elements. So if leetcode makes you better at them, it makes you better at programming. 7k+ stars and 2. Our C Language tutorial is best C language tutorial for beginner and professionals to learn C language, to prepare for practical viva for C language and to learn the concepts by practicing using our C language program examples with simple code samples. There is no need to download anything - Just click on the chapter you wish to begin from, and follow the instructions. Sign up for daily interview questions at ht. Odd Even Linked List; Leetcode -- 227. We start to use backtracking from the second searching. C program to get nth bit of a number January 24, 2016 Pankaj C programming Bitwise operator , C , Program Write a C program to input any number from user and check whether n th bit of the given number is set (1) or not (0). org or mail your article to [email protected] " C program to reverse a string using strrev, without using strrev, recursion and pointers. For example, given. This explains why the example program below prints just one line. See the complete profile on LinkedIn and discover Hua-Ying’s. Q&A for Work. Play Leetcode with different programming language. Given a non-empty, singly linked list with head node head, return a middle node of linked list. In C, mostly, we use “scanf”, “printf”, and other similar functions to control the input and output of our program, while in C++, we use “cin”, “cout”, and other funcitons respectively. Here I think we can assume the hash map data structure has the O(1) complexity, of course you can find(or implement by yourself) solutions for the hash_map in c++ which has the O(1) complexity. Word Search in LeetCode. MAX_VALUE, which was failing some test cases where nodes had that value. Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory. A more thorough test suite would be a starting point to increase it's robustness. // Simple C++ program to display “Hello World” : This line is a comment line. I am having trouble understanding one of a Leetcode Problem. Get Started. · C_Programming. add c to queue when its degree is 0. LeetCode The main pros of LeetCode is their UI. For example, given. For example: Given binary tree [crayon-5e61b1e25795e934700994-i/], [crayon-5e61b1e257967757990153/] …. Count All Valid Pickup and Delivery Options; 花花酱 LeetCode 1349. In summary, I would say that there are no better or worse coding websites, some are simply better suited to a specific purpose. Programming for Everyone by University of Michigan. leetcode help to see help on sub command. Leetcode solutions that look like Fizzbuzz solutions are at the low end of solution quality. Leetcode's Online Code Debugger On ipad, there isn't any Good IDE that provides the debugger. From January 2015, she started to practice leetcode questions; she trains herself to stay focus, develops "muscle" memory when she practices those questions one by one. It's good that within limits the proposed code works. leetcode: Word Break II Instead of returning true or false, word break II asks to record all possible breakings. Analysis: (Dynamic programming)To prevent repeating works, the comparison results should be saved somewhere for future use. One problem can have many tags; Discussion: for each problem, there is a forum thread where people can discuss/share solutions. Problem Statement. com/blog/dynamic-programming/leetcode-115-distinct-subsequences/ 题目分类: DP 动态规划 (Dynamic programming) https. Programming Tutorial , Blogging in Japan Kanji Learning,Darts, Magic , Bar Night life Photo , Video Editing And Rubik's Cube Philipine , English , Japanese Speaker instagram Github twiter Facebook Tumblr Website BuymeCoffe Paypal. Learn How To Find if a Number is a Narcissistic Number or not in C Programming Language. Return True if it is possible that it was your friends name, with some characters (possibly none) being long pressed. I am asking this to finally decide on whether I should start on LeetCode or not to achieve my goal. MIN_VALUE and Integer. competitive programming players study after WalmartLabs codesprint (1) competitive programming study (2) complete sort is a waste (1) Leetcode solution (1) leetcode solutions in github (1) Leetcode submission last 12 months up to May 8 2018 (1) Leetcode summary from 200 to 300 (1). For example, given. Dismiss Join GitHub today. If you have two functions that do different things, it's considered bad style when they have the same name, because that can lead to confusion about what will happen actually when calling the functions. Execution time: 0 ms. [C++] Leetcode: Shuffle an Array not passing. I think the biggest selling point for premium users is the extra problems. Ugly numbers are positive numbers whose prime factors only include 2, 3, 5. Greatest Common Divisor of Strings. C++ Programming Language C++ is a general purpose programming language and widely used now a days for competitive programming. GitHub is home to over 40 million developers working together to host and review code, manage projects, and build software together. The goal of the problem is to test your backtracking coding ability. Given a non-negative integer n. Minimum Cost to Merge Stones. Ex-Google TechLead does some leetcode interview whiteboard practice questions and walks you through solving them. View pull requests data pull requests 50. We can compare the reversed integer with the given integer to check for…. 000 [] 001 [a] 010 [b] 011 [ab] 100 [c] 101 [ac] 110 [bc] 111 [abc] Then the problem is pretty easy, for each number in binary format, check which bit is 1 or 0, we just add the ith number into the set if the ith bit in the number is 1. Given a string s, partition s such that every substring of the partition is a palindrome. Program for Quick Sort in C++. AVI Player: A simple yet useful player for AVI files. You may assume that the maximum length of S is 1000, and there exists one unique longest palindromic substring. The first thing is how to fetch the values between the interval of '. add c to queue when its degree is 0. Use a HashTable to replace the 3D DP array since the DP array could be sparse when many consecutive boxes are the same color. The goal of the problem is to test your backtracking coding ability. C/C++ Coding Exercise, Valid Parentheses - LeetCode Online Judge - Using Stack February 18, 2014 No Comments algorithms , beginner , brainfuck , c / c++ , code , code library , data structure , implementation , programming languages , string. leetcode 48 free-programming-books-zh_CN 38. I am asking this to finally decide on whether I should start on LeetCode or not to achieve my goal. Solve LeetCode problems in VS Code. How to reverse a singly linked list in C. Home >> Programming Questions >> Jewels and Stones LeetCode - Jewels and Stones Java SolutionIn this post, we will see leetcode jewels and stones problem's solution in Java. Level up your coding skills and quickly land a job. It is hard to define what greedy algorithm is. pdf from AA 14/4/2018 Microsoft - LeetCode Microsoft You have solved 31 / 96 problems. You use a dictionary when it is the right thing to use: * Is your data ordered (ie you need to be able to insert data items at specific points) and might needs to be sorted - use a list * Is you data selectable by only a single integer that is gre. Longest Palindromic Substring. I have these values starting as Integer. Want to learn about how to use Regular Expressions/ Java/ SQL/. I'm good at C programming. View Microsoft - LeetCode. Dialects of BASIC, esoteric programming languages, and markup languages are not included. Ex-Google TechLead does some leetcode interview whiteboard practice questions and walks you through solving them. Facebook Coding interview question - Decode Ways (Leetcode) #Facebook #CodingInterview #LeetCode #DecodeWays #Google. My solutions to the programming problems on LeetCode - the famous interview prep website. Second, scan every interval, if it can be merged to the previous one, then merge them, else push it into the result vector. Given a string S and a string T, find the minimum window in S which will contain all the characters in T in complexity O(n). We use cookies for various purposes including analytics. · C_Programming. The knowledge about any programming language increases with how much you practice in it. Home Tags Currently v1 LeetCode 165. Whether or not you think it's a practical kind of programming, you're free to argue (though we probably disagree). To practice for this y. There is a new alien language which uses the latin alphabet. Note: If you are using leetcode-cn. 2 Ways To Check A Narcissistic Number in C Programming. Your content is yours to consume, integrate, and extend. The word can be constructed from letters of sequentially adjacent cell, where "adjacent" cells are those. Leetcode: 3Sum Given an array S of n integers, are there elements a , b , c in S such that a + b + c = 0? Find all unique triplets in the array which gives the sum of zero. com endpoint anymore. Leetcode's Online Code Debugger On ipad, there isn't any Good IDE that provides the debugger. Given a string, your task is to count how many palindromic substrings in this string. The knowledge about any programming language increases with how much you practice in it. java from AA 1package coding. com/discuss/20619/c- I came up with a solution similar to. Java code is formatted by Language Support for Java. You're given strings J representing the types of stones that are jewels, and S representing the stones you have. Blog Podcast: Don't Miss Your Stop. GitHub is home to over 40 million developers working together to host and review code, manage projects, and build software together. Each character in S is a type of stone you have. Coding Interview Questions in C++ with question links, c++ code and explanation. Whether or not you think it's a practical kind of programming, you're free to argue (though we probably disagree). Really really really recommend EPI over CTCI but that is personal preference. GitHub Gist: star and fork KyleMcClay's gists by creating an account on GitHub. I am having trouble understanding one of a Leetcode Problem. The rule of Sudoku is each row should only contains 1 - 9 of each number occurring only once, each column contains 1-9, and each 3 by 3 sub-matrix should contain 1 - 9. To understand this example, you should have the knowledge of the following C programming topics:. leetcode; import java. This project aims at solving LeetCode algorithm problems with pure C Language using as little library functions as I can, which means except memory management functions and few string functions I will implement everything I need such as trees, stacks, queues and hash tables. LeetCode Explore is the best place for everyone to start practicing and learning on LeetCode. [LeetCode] Minimum Window Substring (Java) July 24, 2014 July 24, 2014 by decoet Given a string S and a string T, find the minimum window in S which will contain all the characters in T in complexity O(n). Programming Language: C++. Pure C solution for LeetCode. · C_Programming. Leetcode: Word Search in C++ Given a 2D board and a word, find if the word exists in the grid. A string which remains the same on reversal is a palindrome. You will learn from the very basic but reach to a master level programmer. Curate this topic Add this topic to your repo. They have varying widths and heights, but their bottom edges are collinear, so that they look like buildings on a skyline. You examine the typed characters of the keyboard. Contents 1Rotate Array in Java 7 2Evaluate Reverse Polish Notation 9 3Solution of Longest Palindromic Substring in Java 11. A hub of software engineering career tips, code snippets, interview preparation, and programming in general. [LeetCode][C++, Python] Regular Expression Matching (dynamic programming) Posted on September 17, 2014 by Peng I have previously solved this problem with nondeterministic finite automata (NFA), which is a little complex. Given a string s, partition s such that every substring of the partition is a palindrome. Leetcode: Search in Rotated Sorted Array (4ms) ana Leetcode: Set Matrix Zeroes (84ms) analysis & solu leetcode: Summary Ranges (less 1ms) Analysis and s. In my opinion, it is a very natural solution for problems that it can solve, and any usage of dynamic programming will end up to be "overkill". LeetCode Solutions Program Creek Version 0. Analysis: (Dynamic programming)To prevent repeating works, the comparison results should be saved somewhere for future use. For example see following leetcode link. Array 229 Dynamic Programming 188 Math 171 String 162 Tree 130 Hash Table 123 Depth-first Search 120 Binary Search 84 Greedy 73 Breadth-first Search 66 Two Pointers 60 Stack 54 Backtracking 53 Design 46 Sort 45 Bit Manipulation 44 Graph 40 Linked List 38 Heap 34. The goal of the problem is to test your backtracking coding ability. If I'm reviewing a solution that was from another Leetcode user or Leetcode itself I will give credit below. Return Value A pointer to the first occurrence in str1 of the entire sequence of characters specified in str2, or a null pointer if the sequence is not present in str1. Example: Input: 38 Output: 2 Explanation: The process is like: 3 + 8 = 11, 1 + 1 = 2. Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory. C program to reverse a string that a user inputs. This site contains an old collection of practice dynamic programming problems and their animated solutions that I put together many years ago while serving as a TA for the undergraduate algorithms course at MIT. C program with sample input and output. These are some programs that I have written for personal use. C++ code is formatted by clang-format following the Google C++ Style Guide.