|
| 1 | +```cpp |
| 2 | +class Solution { |
| 3 | +public: |
| 4 | + int maxSum(vector<vector<int>>& matrix, int k){ |
| 5 | + int n = matrix.size(); |
| 6 | + if(n ==0) |
| 7 | + return 0; |
| 8 | + int m = matrix[0].size(); |
| 9 | + set<int> lower; |
| 10 | + |
| 11 | + vector<int> sum(n+1,0); |
| 12 | + vector<int> col_sum(n,0); |
| 13 | + int ans = INT32_MIN /2; |
| 14 | + for(int l = 0 ; l<m ; ++l){ |
| 15 | + // fill_n(sum.begin(), 0, m+1); |
| 16 | + // fill_n(col_sum.begin(), 0, m); |
| 17 | + fill(sum.begin(), sum.end(),0); |
| 18 | + fill(col_sum.begin(),col_sum.end(),0); |
| 19 | + // vector<int> sum(m+1,0); |
| 20 | + // vector<int> col_sum(m,0); |
| 21 | + // cout << "======== l = "<< l << "=========\n"; |
| 22 | + for(int r = l ;r <m ; ++r){ |
| 23 | + lower.clear(); |
| 24 | + lower.insert(0); |
| 25 | + // cout << "======== r = "<< r <<"============\n"; |
| 26 | + for(int i=0 ; i<n ; ++i){ |
| 27 | + col_sum[i] += matrix[i][r]; |
| 28 | + sum[i+1] =sum[i] + col_sum[i]; |
| 29 | + // cout << col_sum[i] << " " <<sum[i+1]<<"\n" ; |
| 30 | + int find = sum[i+1] - k; |
| 31 | + auto it = lower.lower_bound(find); |
| 32 | + if (it != lower.end()){ |
| 33 | + // cout << *it << " " << r<< " " << i << "\n"; |
| 34 | + ans = max(ans, sum[i+1] - *it); |
| 35 | + } |
| 36 | + lower.insert(sum[i+1]); |
| 37 | + } |
| 38 | + // cout << "\n"; |
| 39 | + } |
| 40 | + // cout << "\n"; |
| 41 | + } |
| 42 | + return ans; |
| 43 | + } |
| 44 | + int maxSumSubmatrix(vector<vector<int>>& matrix, int k) { |
| 45 | + int n = matrix.size(); |
| 46 | + if(n ==0) |
| 47 | + return 0; |
| 48 | + int m = matrix[0].size(); |
| 49 | + if(n > m ){ |
| 50 | + return maxSum(matrix,k); |
| 51 | + } |
| 52 | + set<int> lower; |
| 53 | + |
| 54 | + vector<int> sum(m+1,0); |
| 55 | + vector<int> col_sum(m,0); |
| 56 | + int ans = INT32_MIN /2; |
| 57 | + for(int l = 0 ; l<n ; ++l){ |
| 58 | + // fill_n(sum.begin(), 0, m+1); |
| 59 | + // fill_n(col_sum.begin(), 0, m); |
| 60 | + fill(sum.begin(), sum.end(),0); |
| 61 | + fill(col_sum.begin(),col_sum.end(),0); |
| 62 | + // vector<int> sum(m+1,0); |
| 63 | + // vector<int> col_sum(m,0); |
| 64 | + // cout << "======== l = "<< l << "=========\n"; |
| 65 | + for(int r = l ;r <n ; ++r){ |
| 66 | + lower.clear(); |
| 67 | + lower.insert(0); |
| 68 | + // cout << "======== r = "<< r <<"============\n"; |
| 69 | + for(int i=0 ; i<m ; ++i){ |
| 70 | + col_sum[i] += matrix[r][i]; |
| 71 | + sum[i+1] =sum[i] + col_sum[i]; |
| 72 | + // cout << col_sum[i] << " " <<sum[i+1]<<"\n" ; |
| 73 | + int find = sum[i+1] - k; |
| 74 | + auto it = lower.lower_bound(find); |
| 75 | + if (it != lower.end()){ |
| 76 | + // cout << *it << " " << r<< " " << i << "\n"; |
| 77 | + ans = max(ans, sum[i+1] - *it); |
| 78 | + } |
| 79 | + lower.insert(sum[i+1]); |
| 80 | + } |
| 81 | + } |
| 82 | + } |
| 83 | + return ans; |
| 84 | + } |
| 85 | +}; |
| 86 | + |
| 87 | +``` |
0 commit comments