Category: data structure

There is a special keyboard with all keys in a single row. Given a string keyboard of length 26 indicating the layout of the keyboard (indexed from 0 to …

Given an array of integers and a target value, find the number of distinct pairs that sum to the target. The pairs (x,y) and (x’, y’) where x smaller …

Given an array A of integers, we must modify the array in the following way: we choose an i and replace A with -A, and we repeat this process …

Given an array of integers and an integer k, you need to find the number of unique k-diff pairs in the array. Here a k-diff pair is defined as …

Given a list of dominoes, dominoes = is equivalent to dominoes = if and only if either (a==c and b==d), or (a==d and b==c) – that is, one domino …