Combination Sum

In combination sum problem we have given an array of positive integers arr[] and a sum s, find all unique combinations of elements in arr[] where the sum of those elements is equal to s. The same repeated number may be chosen from arr[] an unlimited number of times. Elements …

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Next Permutation

In the next permutation problem we have given a word, find the lexicographically greater_permutation of it. Example input : str = “tutorialcup” output : tutorialpcu input : str = “nmhdgfecba” output : nmheabcdfg input : str = “algorithms” output : algorithsm input : str = “spoonfeed” output : Next Permutation …

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Longest Common Subsequence

You are given two strings str1 and str2, find out the length of the longest common subsequence. Subsequence: a subsequence is a sequence that can be derived from another sequence by deleting some or no elements without changing the order of the remaining elements. For ex ‘tticp‘ is the subsequence …

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Max Area of Island

Problem Description: Given a 2D matrix, the matrix has only 0(representing water)  and 1(representing land) as entries. An island in the matrix is formed by grouping all the adjacent 1’s connected 4-directionally(horizontal and vertical). Find the maximum area of the island in the matrix. Assume that all four edges of …

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Unique Paths

A m x n 2D  grid is given and you are standing at the topmost and leftmost cell in the grid. i.e. the cell located at (1,1). Find the number of unique paths that can be taken to reach a cell located at (m,n) from the cell located at (1,1) …

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