Company: citi_14oct
Difficulty: medium
Find Common Letter Pair Problem Description You are given an array S consisting of N strings. Every string is of the same length M . Your task is to find a pair of strings in array S , such that there exists a position in which both of the strings have the same letter. Both the index in array S and the positions in the strings are numbered from zero. For example, given S = ["abc", "bca", "dbe"] , string 0 ("abc") and string 2 ("dbe") have the same letter 'b' in position 1. On the other hand, for strings "abc" and "bca" there does not exist a position in which they have the same letter. Write a function: vector<int> solution(vector<string> &S); that, given a zero-indexed array S of N strings, returns an array describing a pair of strings from S which share a common letter at some index. If there is no such pair, the function should return an empty array. If there is more than one correct answer, the function can return any of them. The result should be represented as an