算法总结之 子矩阵的最大累加和问题

package TT;

public class Test77 {

     public static int maxSum(int[][] m){
          if(m==null || m.length==0 || m[0].length==0){
              return 0;
          }
          
          int max  = Integer.MIN_VALUE;
          int cur = 0;
          int[] s = null;
          
          for(int i =0; i!=m.length; i++){
              s = new int[m[0].length];
              for (int j = i; j != m.length; j++) {
                cur = 0;
                for(int k =0; k!=s.length; k++){
                    s[k] +=m[j][k];
                    cur += s[k];
                    max = Math.max(max,cur);
                    cur = cur <0 ? 0 : cur;
                }
            }
          }
          
          return max;
     }
    
     public static void main(String[] args){
         
         
          int[][] a = new int[3][3];
          a[0][0]=-90;
          a[0][1]=-48;
          a[0][2]=78;
          a[1][0]=64;
          a[1][1]=-40;
          a[1][2]=64;
          a[2][0]=-81;
          a[2][1]=-7;
          a[2][2]=66;
          
          int x = maxSum(a);
          
          System.out.println(x);
          
          
         
         
     }
     
     
    
}