Jump Search Algorithm In Java

Jump search algorithm is a pretty new algorithm to search for an element in a sorted array. The idea of jump search is to skip the number of comparisons by jumping the indices by length m while performing the searching thus getting a better time complexity than linear search. For jump search m is determined…… Continue reading Jump Search Algorithm In Java

Leetcode Unique Paths Java Solution

A robot is located at the top-left corner of a m x n grid (marked ‘Start’ in the diagram below). The robot can only move either down or right at any point in time. The robot is trying to reach the bottom-right corner of the grid (marked ‘Finish’ in the diagram below). How many possible unique paths are there?…… Continue reading Leetcode Unique Paths Java Solution

Leetcode Find the Duplicate Number Solution Java Solution

Given an array nums containing n + 1 integers where each integer is between 1 and n (inclusive), prove that at least one duplicate number must exist. Assume that there is only one duplicate number, find the duplicate one. Example 1: Input: [1,3,4,2,2] Output: 2 Example 2: Input: [3,1,3,4,2] Output: 3 Note: You must not modify the array (assume the array is read…… Continue reading Leetcode Find the Duplicate Number Solution Java Solution

Leetcode 59 Spiral Matrix II Java Solution

Given a positive integer n, generate a square matrix filled with elements from 1 to n2 in spiral order. Example: Input: 3 Output: [ [ 1, 2, 3 ], [ 8, 9, 4 ], [ 7, 6, 5 ] ] Solution 1: class Solution { public int[][] generateMatrix(int num) { int[][] spiralMatrix = new int[num][num]; int m =…… Continue reading Leetcode 59 Spiral Matrix II Java Solution

Leetcode 54 Spiral Matrix Java Solution

Given a matrix of m x n elements (m rows, n columns), return all elements of the matrix in spiral order. Example 1: Input: [ [ 1, 2, 3 ], [ 4, 5, 6 ], [ 7, 8, 9 ] ] Output: [1,2,3,6,9,8,7,4,5] Example 2: Input: [ [1, 2, 3, 4], [5, 6, 7, 8], [9,10,11,12] ] Output: [1,2,3,4,8,12,11,10,9,5,6,7] Solution 1: class…… Continue reading Leetcode 54 Spiral Matrix Java Solution

Leetcode 53 Maximum Subarray Java Solution

Given an integer array nums, find the contiguous subarray (containing at least one number) which has the largest sum and return its sum. Example: Input: [-2,1,-3,4,-1,2,1,-5,4], Output: 6 Explanation: [4,-1,2,1] has the largest sum = 6. Follow up: If you have figured out the O(n) solution, try coding another solution using the divide and conquer approach, which is…… Continue reading Leetcode 53 Maximum Subarray Java Solution

Leetcode 49 Group Anagrams Java Solution

Given an array of strings, group anagrams together. Example: Input: [“eat”, “tea”, “tan”, “ate”, “nat”, “bat”], Output: [ [“ate”,”eat”,”tea”], [“nat”,”tan”], [“bat”] ] Note: All inputs will be in lowercase.The order of your output does not matter. Solution 1: class Solution { public List<List<String>> groupAnagrams(String[] strs) { Map<String, List<String>> anMap = new HashMap<String, List<String>>(); List<List<String>> retList =…… Continue reading Leetcode 49 Group Anagrams Java Solution

Leetcode 46 Permutations Java Solution

Given a collection of distinct integers, return all possible permutations. Example: Input: [1,2,3] Output: [ [1,2,3], [1,3,2], [2,1,3], [2,3,1], [3,1,2], [3,2,1] ] Solution 1: class Solution { List<List<Integer>> returnList = new ArrayList<>(); int[] used ; public List<List<Integer>> permute(int[] nums) { List<Integer> temp = new ArrayList<Integer>(); used = new int[nums.length]; findPermutations(nums, 0, temp); return returnList; } public void…… Continue reading Leetcode 46 Permutations Java Solution

Leetcode 41 First Missing Positive Java Solution

Given an unsorted integer array, find the smallest missing positive integer. Example 1: Input: [1,2,0] Output: 3 Example 2: Input: [3,4,-1,1] Output: 2 Example 3: Input: [7,8,9,11,12] Output: 1 Note: Your algorithm should run in O(n) time and uses constant extra space. Solution 1: class Solution { public int firstMissingPositive(int[] nums) { for(int i=0;i<nums.length;i++){ if(nums[i]>0 && nums[i]!=…… Continue reading Leetcode 41 First Missing Positive Java Solution

Leetcode 37 Sudoku Solver Java Solution

Write a program to solve a Sudoku puzzle by filling the empty cells. A sudoku solution must satisfy all of the following rules: Each of the digits 1-9 must occur exactly once in each row.Each of the digits 1-9 must occur exactly once in each column.Each of the the digits 1-9 must occur exactly once in each of the 9 3×3 sub-boxes of the grid. Empty cells are…… Continue reading Leetcode 37 Sudoku Solver Java Solution