Maximal Square (dp,cpp,leetcode)

Given a 2D binary matrix filled with 0's and 1's, find the largest square 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: 4 

problem link======  https://leetcode.com/problems/maximal-square/ 

========================================================================================== 

class Solution {
public:
    int maximalSquare(vector<vector<char>>& matrix) 
    {
          int maxm=0;
        if(matrix.size()==0)
            return 0;
        int t[matrix.size()][matrix[0].size()];
        
        memset(t,0,sizeof(t));
        
        for(int i=0;i<matrix.size();i++)
        {
          t[i][0]=matrix[i][0]-48;
            if(maxm<t[i][0])
                maxm=t[i][0];
        }
        
      for(int i=0;i<matrix[0].size();i++)
        {
          t[0][i]=matrix[0][i]-48;
          if(maxm<t[0][i])
                maxm=t[0][i];
        }
        
        
        
     
        
         for(int i=1;i<matrix.size();i++)
        {
         for(int j=1;j<matrix[0].size();j++)
         {
            if(matrix[i][j]=='1')
             {
                 t[i][j]=   1+ min(  t[i-1][j-1],  min(t[i-1][j],t[i][j-1]) );
                
                  // maxm=max(maxm,t[i][j]);
                if(maxm<t[i][j])
                    maxm=t[i][j];
             }
         }
        }
        
        
        return maxm*maxm;
      
       
        
    }
};