Software Engineer

You are given an array of integers ARR[] of size N consisting of zeros and ones. You have to select a subset and flip bits of that subset. You have to return the count of maximum one’s that you can obtain by flipping chosen sub-array at most once.

A flip operation is one in which you turn 1 into 0 and 0 into 1.

For example:

If you are given an array {1, 1, 0, 0, 1} then you will have to return the count of maximum one’s you can obtain by flipping anyone chosen sub-array at most once, so here you will clearly choose sub-array from the index 2 to 3 and then flip it's bits. So, the final array comes out to be {1, 1, 1, 1, 1} which contains five ones and so you will return 5.

You are given a 2-dimensional array/list having N rows and M columns, which is filled with ones(1) and zeroes(0). 1 signifies land, and 0 signifies water.

A cell is said to be connected to another cell, if one cell lies immediately next to the other cell, in any of the eight directions (two vertical, two horizontal, and four diagonals).

A group of connected cells having value 1 is called an island. Your task is to find the number of such islands present in the matrix.