SDE - Intern

You are given a six sided dice. You toss it n number of time. Find the probability of getting exactly k '6's.

Ninja has two strings ‘s’ and ‘t’ of same length, he knows that both strings are equivalent strings which means s[i], t[i] will follow all rules of any equivalence relation that are:

Reflexive : s[i] = t[i]

Symmetric: s[i] = t[i] => t[i] = s[i]

Transitive: if s[i] = t[i] and t[i] = s[j] then s[i] = s[j]

Ninja wants your help to find the lexicographically smallest equivalent string of a given string ‘str’.

Note:

1. String ‘s’, ‘t’ and ‘str’ consist of only lowercase English letters from ‘a’ – ‘z’.
2. String ‘s’ and ‘t’ are of same length.

For example:

Let s = “abc” , t = “xyz” and str = “xbc” then all strings that we can generate are “abc”, “abz”, “ayc”,”ayz”, “xbc”, “xbz”, “xyc”, “xyz” and smallest of all these is “abc”. 

You have been given a non-empty grid consisting of only 0s and 1s. You have to find the number of islands in the given grid.

An island is a group of 1s (representing land) connected horizontally, vertically or diagonally. You can assume that all four edges of the grid are surrounded by 0s (representing water).

You have to design an OTP system for users.