leetcode.221. Maximal Square

Given a 2D binary matrix filled with 0's and 1's, find the largest square containing all 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<vector<char>>& matrix) {
         int height=matrix.size(); 
         if(height==0)
             return 0;
             
         int width=matrix[0].size();
         vector<vector<int>> vec(height,vector<int>(width,0));
         int result=0; 
         for(int i=0;i<height;i++)
         { 
             for(int j=0;j<width;j++) 
             {
                 if(matrix[i][j]=='1')
                 { 
                     vec[i][j]=1; 
                     if(i>0&&j>0)
                       vec[i][j]=min(min(vec[i-1][j],vec[i][j-1]),vec[i-1][j-1])+1; 
                     
                 } 
                 result=max(result,vec[i][j]);
            } 
             
         } 
         return result*result;
    }
};