Maximal Rectangle

Given a 2D binary matrix filled with 0’s and 1’s, find the largest rectangle containing only 1’s and return its area. Example: Input: [ [“1″,”0″,”1″,”0″,”0”], [“1″,”0″,”1″,”1″,”1”], [“1″,”1″,”1″,”1″,”1”], [“1″,”0″,”0″,”1″,”0”] ] Output: 6 Solution C# Program