SDE - 1

You are given a string 'Str' consisting of 'N' lowercase Latin letters. You have to find the longest substring of the given string without repeating characters.

String ‘B’ is a substring of string ‘A’ if it can be obtained from ‘A’ by deletion of several (possibly, zero or all) characters from the beginning and several (possibly, zero or all) characters from the end.

For Example :

If the given input string is "aabc", then you should return "abc" as the longest substring without repeating characters.

Note :

If there are multiple substrings with the same length, then you should print the substring which comes earlier in the given string. 

For Example :

If the given input string is "abcda", here “abcd” and “bcda” can be the longest unique substring but “abcd” comes earlier in the given string. So we will print “abcd” as the longest unique substring.

You are given string S of length N, and an integer K. Your task is to find the length of the longest substring that contains at most K distinct characters.

Ninja has given a list of unique words 'WORDS' of size 'N' and he wants to find all the words in the list formed after concatenating two or more words in the same list.

As Ninja's best friend, he asked you to help him with the above problem. So, your task is to find all words in the list which are formed after concatenating two or more words in the same list.

Print words in any order.

Note: One word can be concatenated multiple times. It is guaranteed that there is at least one word in the list, which is formed after concatenating two or more words.

Example:

Input: 'WORDS' = ["ninjas", "coding", "codingninjas"]
Output: ["codingninjas"]

Only word "codingninjas' is formed after concatenating two or more words in the list i.e "coding" and "ninjas".

You are playing a video game, which contains an N x N grid. You start on the top left cell of the grid, and are free to move anywhere through the grid, any number of times.

Each cell in the grid has some number of points that you can collect from it and you can collect points at most once from each cell. Furthermore, it is possible to collect points from a cell, if and only if the cell lies on one of the two diagonals of the grid. Print the maximum number of points you can collect, given the grid.

For example:

If the grid is:
1 2
3 4
We can collect points from all cells as each cell lies on a diagonal. So, the maximum points will be 1+2+3+4 = 10.