컴퓨터공학/LeetCode Solutions

[LeetCode] 20. Valid Parentheses

20. Valid Parentheses Easy Given a string s containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid. An input string is valid if: Open brackets must be closed by the same type of brackets. Open brackets must be closed in the correct order. Every close bracket has a corresponding open bracket of the same type. Example 1: Input: s = "()" Output: true ..

[LeetCode] 412. Fizz Buzz

412. Fizz Buzz Easy Given an integer n, return a string array answer (1-indexed) where: answer[i] == "FizzBuzz" if i is divisible by 3 and 5. answer[i] == "Fizz" if i is divisible by 3. answer[i] == "Buzz" if i is divisible by 5. answer[i] == i (as a string) if none of the above conditions are true. Example 1: Input: n = 3 Output: ["1","2","Fizz"] Example 2: Input: n = 5 Output: ["1","2","Fizz",..

[LeetCode] 290. Word Pattern

290. Word Pattern Easy Given a pattern and a string s, find if s follows the same pattern. Here follow means a full match, such that there is a bijection between a letter in pattern and a non-empty word in s. Example 1: Input: pattern = "abba", s = "dog cat cat dog" Output: true Example 2: Input: pattern = "abba", s = "dog cat cat fish" Output: false Example 3: Input: pattern = "aaaa", s = "dog ..

[LeetCode] 217. Contains Duplicate

217. Contains Duplicate Easy Given an integer array nums, return true if any value appears at least twice in the array, and return false if every element is distinct. Example 1: Input: nums = [1,2,3,1] Output: true Example 2: Input: nums = [1,2,3,4] Output: false Example 3: Input: nums = [1,1,1,3,3,4,3,2,4,2] Output: true Constraints: 1

[LeetCode] 344. Reverse String

344. Reverse String Easy Write a function that reverses a string. The input string is given as an array of characters s. You must do this by modifying the input array in-place with O(1) extra memory. Example 1: Input: s = ["h","e","l","l","o"] Output: ["o","l","l","e","h"] Example 2: Input: s = ["H","a","n","n","a","h"] Output: ["h","a","n","n","a","H"] Constraints: 1

[LeetCode] 88. Merge Sorted Array

88. Merge Sorted Array Easy You are given two integer arrays nums1 and nums2, sorted in non-decreasing order, and two integers m and n, representing the number of elements in nums1 and nums2 respectively. Merge nums1 and nums2 into a single array sorted in non-decreasing order. The final sorted array should not be returned by the function, but instead be stored inside the array nums1. To accommo..