Added solution

Author: avidLearnerInProgress

maximal_square.cpp

@@ -0,0 +1,43 @@
+class Solution {
+public:
+    int maximalSquare(vector<vector<char>>& matrix) {
+        
+        if(matrix.size() == 0) return 0;
+        
+        int m = matrix.size(), n = matrix[0].size();
+        vector<vector<int>> globalSum(m + 1, vector<int>(n + 1));
+        
+        /*for(auto i : globalSum){
+            for(auto j: i){
+                cout<<j<<" ";
+            }
+            cout<<"\n";
+        }*/
+        
+        /*for(int i=0; i<m; i++) // first column
+            globalSum[i][0] = matrix[i][0] - '0';
+        
+        for(int i=0; i<n; i++) //first row
+            globalSum[0][i] = matrix[0][i] - '0';*/
+        
+        auto globalMax = 0;
+        for(int i=1; i<m+1; i++){
+            for(int j=1; j<n+1; j++){
+                    globalSum[i][j] = matrix[i-1][j-1] == '0'? 0 : 
+                (min(globalSum[i][j-1], min(globalSum[i-1][j-1], globalSum[i-1][j])) + 1);
+                globalMax = max(globalMax, globalSum[i][j]);
+            }
+        }
+        
+        cout<<"\n";
+        for(auto i:globalSum){
+            for(auto j:i){
+                cout<<j<<" ";
+            }
+            cout<<"\n";
+        }
+        
+        return globalMax * globalMax;
+        //return 0;
+    }
+};