Problem Given a sorted array and an element, find the first occurrence of key in array. As array can contain duplicate values, there can be multiple occurrences of same element, problem is to find first index. Examples Example 1: Input: a = [1, 4, 4, 10, 10, 15, 20], target = 10 Output: 3 ...
Problem Given an integer array nums where the elements are sorted in ascending order, convert it to a height-balanced binary search tree. Examples Example 1: Input: nums = [1, 2, 3, 4, 5, 6] Output: [3,2,5,1,null,4,6] Explanation: [4,2,5,1,3,null,6] is also accepted. ...
Problem Given the head of a sorted singly linked list and a target value, implement a function to find the target value using a binary search approach. If the target is found in the linked list, return the node; otherwise, return None. Examples Example 1: Input: head = [1, 3, 5, 7, 9, 11], target = 7 Output: Node with value 7 Explanation: The target 7 is found in the linked list. ...
Problem Given two sorted arrays nums1 and nums2 of size m and n respectively, return the median of the two sorted arrays. The overall run time complexity should be O(log (m+n)). Examples Example 1: Input: nums1 = [1,3], nums2 = [2] Output: 2.00000 Explanation: merged array = [1,2,3] and median is 2. ...
Problem Given a sorted array arr[] of n elements, write a function to search a given element x in arr[]. Input: A sorted array, arrA[] and an key Output : Return index if element is found, else -1. Examples Example 1: Input: nums = [-1,0,3,5,9,12], target = 9 Output: 4 Explanation: 9 exists in nums and its index is 4 ...
Problem Follow up for “Find Minimum in Rotated Sorted Array”: What if duplicates are allowed? Would this affect the run-time complexity? How and why? This is follow up of - Find Minimum in Rotated Sorted Array 1 - No duplicates allowed Examples Example 1: Input: nums = [1,3,5] Output: 1 ...
Problem Follow up for Remove duplicates from Sorted Array I: What if duplicates are allowed at most twice? OR Given an integer array nums sorted in non-decreasing order, remove some duplicates in-place such that each unique element appears at most twice. The relative order of the elements should be kept the same. 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 Given an array of integers nums sorted in non-decreasing order, find the starting and ending position of a given target value. If target is not found in the array, return [-1, -1]. You must write an algorithm with O(log n) runtime complexity. Examples Example 1: Input: nums = [5,7,7,8,8,10], target = 8 Output: [3,4] ...
Problem Suppose a sorted array is rotated at some pivot unknown to you beforehand. (i.e., [0, 1, 2, 4, 5, 6, 7] might become [4, 5, 6, 7, 0, 1, 2]). You are given a target value to search. If found in the array return its index, otherwise return -1. You may assume no duplicate exists in the array. Follow up: what if duplicates are allowed? ...
Problem Given a sorted integer array nums and an integer n, add/patch elements to the array such that any number in the range [1, n] inclusive can be formed by the sum of some elements in the array. Return the minimum number of patches required. Examples Example 1: Input: nums = [1,3], n = 6 Output: 1 Explanation: Combinations of nums are [1], [3], [1,3], which form possible sums of: 1, 3, 4. Now if we add/patch 2 to nums, the combinations are: [1], [2], [3], [1,3], [2,3], [1,2,3]. Possible sums are 1, 2, 3, 4, 5, 6, which now covers the range [1, 6]. So we only need 1 patch. ...