Merge pull request #1826 from saurabhkumar1432/master

maximum rectangle sum

Program's_Contributed_By_Contributors/rectangle sum.cpp

@@ -0,0 +1,68 @@
+//saurabh kumar
+//https://github.com/saurabhkumar1432
+//date-1 october 2022 
+//time - 00:26
+class Solution {
+public:
+    int maxSumSubmatrix(vector<vector<int>>& matrix, int k) {
+         int m=matrix.size(),n=matrix[0].size();
+        vector<vector<int>>dp(m+1,vector<int>(n,0));
+        for(int i=0;i<m;i++){
+            for(int j=0;j<n;j++){
+                dp[i+1][j]=dp[i][j]+matrix[i][j];
+            }
+        }
+        int ans=INT_MIN;
+        for(int i=0;i<m;i++){
+            for(int l=i+1;l<=m;l++){
+                for(int j=0;j<n;j++){
+                    int val=0;
+                    for(int k=j;k<n;k++){
+                        val+=dp[l][k]-dp[i][k];
+
+                        if(val<k){
+                            ans=max(ans,val);
+                        }
+                        else if(val==k){
+                            return k;
+                        }
+                    }
+                }
+            }
+        }
+        return ans;
+
+    }
+};
+class Solution {
+public:
+    int maxSumSubmatrix(vector<vector<int>>& matrix, int k) {
+         int m=matrix.size(),n=matrix[0].size();
+        vector<vector<int>>dp(m+1,vector<int>(n,0));
+        for(int i=0;i<m;i++){
+            for(int j=0;j<n;j++){
+                dp[i+1][j]=dp[i][j]+matrix[i][j];
+            }
+        }
+        int ans=INT_MIN;
+        for(int i=0;i<m;i++){
+            for(int l=i+1;l<=m;l++){
+                for(int j=0;j<n;j++){
+                    int val=0;
+                    for(int k=j;k<n;k++){
+                        val+=dp[l][k]-dp[i][k];
+
+                        if(val<k){
+                            ans=max(ans,val);
+                        }
+                        else if(val==k){
+                            return k;
+                        }
+                    }
+                }
+            }
+        }
+        return ans;
+
+    }
+};