0 -2 -7 0
 9 2 -6 2
-4 1 -4 1
-1 8 0 -2 

 9 2
-4 1
-1 8

 0 -2 -7 0
 9 2 -6 2

 9 2 -6 2
-4 1 -4 1

-4 1 -4 1
-1 8 0 -2 

public int maxSubsequence(int[] array) {
 if (array.length == 0) {
 return 0;
 }
 int max = Integer.MIN_VALUE;
 int[] maxSub = new int[array.length];
 maxSub[0] = array[0];
 
 for (int i = 1; i < array.length; i++) {
 maxSub[i] = (maxSub[i-1] > 0) ? (maxSub[i-1] + array[i]) : array[i]; 
 if (max < maxSub[i]) {
 max = maxSub[i];
 }
 }
 return max;
 }

 9 2 -6 2
-4 1 -4 1
-1 8 0 -2 

int[][] total = matrix;
for (int i = 1; i < matrix[0].length; i++) {
 for (int j = 0; j < matrix.length; j++) {
 total[i][j] += total[i-1][j];
 }
}

public int subMaxMatrix(int[][] matrix) {
 
 int[][] total = matrix;
 for (int i = 1; i < matrix[0].length; i++) {
 for (int j = 0; j < matrix.length; j++) {
 total[i][j] += total[i-1][j];
 }
 }
 
 int maximum = Integer.MIN_VALUE;
 for (int i = 0; i < matrix.length; i++) {
 for (int j = i; j < matrix.length; j++) {
 //result 保存的是从 i 行 到第 j 行 所对应的矩阵上下值的和
        int[] result = new int[matrix[0].length];
 for (int f = 0; f < matrix[0].length; f++) {
  if (i == 0) {
  result[f] = total[j][f];
  } else {
  result[f] = total[j][f] - total[i - 1][f];
  }
 }
 int maximal = maxSubsequence(result);
 
 if (maximal > maximum) {
  maximum = maximal;
 }
 }
 }
 
 return maximum;
 }

 0 -2 -7 0 
 9 2 -6 2 
 -4 1 -4 1 
 -1 8 0 -2 

 9 2 
 -4 1 
 -1 8 

 #include <stdio.h> 
 #include <stdlib.h> 
  
 int main(void) 
 { 
  int i, j, h, k, n, max, sum, cur, matrix[101][101]; 
  
  while (scanf("%d", &n) != EOF) { 
   // 初始化接收矩阵 
   for (i = 0; i < n; i ++) { 
    for (j = 0; j < n; j ++) 
     scanf("%d", *(matrix + i) + j); 
   } 
  
   // 动态规划(类似于一维数组连续最大子序列和) 
   max = matrix[0][0]; 
  
   for (i = 0; i < n; i ++) { 
    // i，j确定上下界 
    for (j = i; j < n; j ++) {  
     // 初始化 
     for (k = i, sum = 0; k <= j; k ++) 
      sum += matrix[k][0]; 
     if (sum > max) 
      max = sum; 
  
     for (h = 1; h < n; h ++) { 
      for (k = i, cur = 0; k <= j; k ++) 
       cur += matrix[k][h]; 
  
      if (sum >= 0) 
       sum += cur; 
      else 
       sum = cur; 
  
      if (sum > max) max = sum; 
     } 
    } 
   } 
  
   printf("%d\n", max); 
  } 
  
  return 0; 
 }