题目:
题解:
java
class Solution {
public int maxSumSubmatrix(int[][] matrix, int k) {
int ans = Integer.MIN_VALUE;
int m = matrix.length, n = matrix[0].length;
for (int i = 0; i < m; ++i) { // 枚举上边界
int[] sum = new int[n];
for (int j = i; j < m; ++j) { // 枚举下边界
for (int c = 0; c < n; ++c) {
sum[c] += matrix[j][c]; // 更新每列的元素和
}
TreeSet<Integer> sumSet = new TreeSet<Integer>();
sumSet.add(0);
int s = 0;
for (int v : sum) {
s += v;
Integer ceil = sumSet.ceiling(s - k);
if (ceil != null) {
ans = Math.max(ans, s - ceil);
}
sumSet.add(s);
}
}
}
return ans;
}
}