Num of Islands (medium)

From a 2D array (matrix) containing only 1s(land) and null(water), count the number of islands in it. An island is a connected set of 1s(land) and is surrounded by either an edge or null(water). Each cell is considered connected to other cells horizontally or vertically (not diagonally).

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Find The Most Frequent Element in an Array (easy)

Write input with number separeted by commas, it will be transformed into an array so it can be calculated. Ex) 4,5,2,1,1.

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