221. Maximal Square

Given a 2D binary matrix filled with 0's and 1's, find the largest square containing only 1's and return its area.

For example, given the following matrix:

1 0 1 0 0
1 0 1 1 1
1 1 1 1 1
1 0 0 1 0

Return 4.

class Solution {
public:
    int maximalSquare(vector>& matrix) {
        if(matrix.empty()||matrix[0].empty())
           return 0;
        int m = matrix.size();
        int n = matrix[0].size();
        
        vector> dp(m,vector(n,0));
        int maxArea = 0;
        for(int i=0;i