Max Sum of Rectangle No Larger Than K

对于一维数组求最大的和并且不大于K

class Solution {
public:
int maxSumSubmatrix(vector<vector<int>>& matrix, int k) {
if (matrix.empty())
return 0;
int row = matrix.size();
int col = matrix[0].size();
int res = numeric_limits<int>::min();
for (int l = 0; l < col; l++) {
vector<int>sums(row, 0);
for (int r = l; r < col; ++r) {
for (int i = 0; i < row; ++i) {
sums[i] += matrix[i][r];
}

//Find the max subarray no more than k
set<int> accuSet;
accuSet.insert(0);
int curSum = 0, CurMax = numeric_limits<int>::min();
for (int sum : sums) {
curSum += sum;
set<int>::iterator it = accuSet.lower_bound(curSum - k);
if (it != accuSet.end())
CurMax = max(CurMax, curSum - *it);
accuSet.insert(curSum);

}
res = max(res, CurMax);
}
}
return res;
}
};