Given a sorted array and a target value, return the index if the target is found. If not, return the index where it would be if it were inserted in order. You may assume no duplicates in the array. Example 1: Input: [1,3,5,6], 5 Output: 2 Example 2: Input: [1,3,5,6], 2 Output: 1 Example 3:…… Continue reading Leetcode 35 Search Insert Position Java Position
Tag: Leetcode
Leetcode 33 Search in Rotated Sorted Array Java Solution
Suppose an array sorted in ascending order 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. Your algorithm’s runtime complexity must be in the order of O(log n).…… Continue reading Leetcode 33 Search in Rotated Sorted Array Java Solution
Leetcode 31 Next Permutation Java Solution
Implement next permutation, which rearranges numbers into the lexicographically next greater permutation of numbers. If such arrangement is not possible, it must rearrange it as the lowest possible order (ie, sorted in ascending order). The replacement must be in-place and use only constant extra memory. Here are some examples. Inputs are in the left-hand column and its corresponding outputs…… Continue reading Leetcode 31 Next Permutation Java Solution
Leetcode 787 Cheapest Flights Within K Stops Java Solution
There are n cities connected by m flights. Each flight starts from city u and arrives at v with a price w. Now given all the cities and flights, together with starting city src and the destination dst, your task is to find the cheapest price from src to dst with up to k stops. If there is no…… Continue reading Leetcode 787 Cheapest Flights Within K Stops Java Solution
Leetcode 27 Remove Element Java Solution
Given an array nums and a value val, remove all instances of that value in-place and return the new length. Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory. The order of elements can be changed. It doesn’t matter what you leave beyond the new length. Example 1: Given nums…… Continue reading Leetcode 27 Remove Element Java Solution
Leetcode 26 Remove Duplicates from Sorted Array Java Solution
Given a sorted array nums, remove the duplicates in-place such that each element appear only once and return the new length. Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory. Example 1: Given nums = [1,1,2], Your function should return length = 2, with the first two elements of nums…… Continue reading Leetcode 26 Remove Duplicates from Sorted Array Java Solution
Leetcode 24 Swap Nodes in Pairs Java Solution
Given a linked list, swap every two adjacent nodes and return its head. You may not modify the values in the list’s nodes, only nodes itself may be changed. Example: Given 1->2->3->4, you should return the list as 2->1->4->3. Solution 1: public class Solution { public ListNode swapPairs(ListNode head) { if(head == null || head.next == null) return…… Continue reading Leetcode 24 Swap Nodes in Pairs Java Solution
Leetcode 21 Merge Two Sorted Lists Java Solution
Merge two sorted linked lists and return it as a new sorted list. The new list should be made by splicing together the nodes of the first two lists. Example: Input: 1->2->4, 1->3->4 Output: 1->1->2->3->4->4 Solution 1: public class Solution { public ListNode mergeTwoLists(ListNode l1, ListNode l2) { ListNode p1 = l1; ListNode p2 = l2; ListNode…… Continue reading Leetcode 21 Merge Two Sorted Lists Java Solution
Leetcode 20 Valid Parentheses Java Solution
Given a string 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. Note that an empty string is also considered valid. Example 1: Input: “()” Output: true Example 2:…… Continue reading Leetcode 20 Valid Parentheses Java Solution
Leetcode 19 Remove Nth Node From End of List Java Solution
Given a linked list, remove the n-th node from the end of list and return its head. Example: Given linked list: 1->2->3->4->5, and n = 2. After removing the second node from the end, the linked list becomes 1->2->3->5. Solution 1: public class Solution { public ListNode removeNthFromEnd(ListNode head, int n) { if(head == null) return…… Continue reading Leetcode 19 Remove Nth Node From End of List Java Solution