Problem You are given an array prices where prices[i] is the price of a given stock on the ith day. You want to maximize your profit by choosing a single day to buy one stock and choosing a different day in the future to sell that stock. Return the maximum profit you can achieve from this transaction. If you cannot achieve any profit, return 0. OR ...
Problem Write an algorithm to find Whether Given String is palindrome or Not. Definition Palindrome Definition Examples Example 1: Input: str = "malayalam" Output: true Example 2: Input: str = "abc" Output: false Solution Method 1 - Recursion Algorithm If the first and last characters don’t match, return false (not a palindrome). If they match, remove the first and last characters and call the function recursively with the remaining substring. This continues until the entire string is checked. Code Java public Boolean isPalindrome(String s) { if (s.length()<2) { return true; } if (s.charAt(0) == s.charAt(s.length() - 1)) { return isPalindrome(s.substring(1, s.length() - 1)); } else { return false; } } ...
Problem Given two sorted integer arrays A and B, merge B into A as one sorted array. Note: You may assume that A has enough space to hold additional elements from B. The number of elements initialized in A and B are m and n respectively. Similar Problem 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. ...
Problem Given an integer array nums, move all 0’s to the end of it while maintaining the relative order of the non-zero elements. Note that you must do this in-place without making a copy of the array. Examples Example 1: Input: nums = [0,1,0,3,12] Output: [1,3,12,0,0] Example 2: Input: nums = [0] Output: [0] ...
Problem Given an array of numbers sorted in increasing order, return a new array containing squares of all the numbers of the input array sorted in increasing order. Examples Example 1: Input: a[] = [-5, -2, -1, 0, 4, 6] Output: [0, 1, 4, 16, 25, 36] Explanation: After squaring, the array becomes [25, 4, 1, 0, 16, 36]. After sorting, it becomes [0, 1, 4, 16, 25, 36]. ...
Problem Given an array A of integers and integer K, return the maximum S such that there exists i < j with A[i] + A[j] = S and S < K. If no i, j exist satisfying this equation, return -1. Examples Example 1: Input: A = [34,23,1,24,75,33,54,8], K = 60 Output: 58 Explanation: We can use 34 and 24 to sum 58 which is less than 60. ...
Problem Given a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring cases. Palindrome Definition Examples Example 1: Input: s = "A man, a plan, a canal: Panama" Output: true Explanation: "amanaplanacanalpanama" is a palindrome. Example 2: Input: s = "race a car" Output: false Explanation: "raceacar" is not a palindrome. ...
Problem Given an integer array nums sorted in non-decreasing order, remove the duplicates in-place such that each unique element appears only once. The relative order of the elements should be kept the same. Then return the number of unique elements in nums. Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory. Note that even though we want you to return the new length, make sure to change the original array as well in place. ...
Problem Given an integer array nums and an integer val, remove all occurrences of val in nums in-place. The relative order of the elements may be changed. Since it is impossible to change the length of the array in some languages, you must instead have the result be placed in the first part of the array nums. More formally, if there are k elements after removing the duplicates, then the first k elements of nums should hold the final result. It does not matter what you leave beyond the first k elements. ...
Problem Reverse a linked list. Follow up 1 - Do it in-place and in one-pass. Follow up 2 - Can you do it with only 2 pointers. Examples For example: Input: 1->2->3->4->5->NULL Output: 5->4->3->2->1->NULL ...