Merge pull request #6 from anushkaGurjar99/master

dnshi · web-flow · commit b2a9b1989a97 · 2020-10-16T03:14:59.000-07:00
Added 73.set matrix zeros.cpp
diff --git a/algorithms/setMatrixZeros.cpp b/algorithms/setMatrixZeros.cpp
@@ -0,0 +1,77 @@
+
+#include<bits/stdc++.h>
+using namespace std;
+
+// Problem Statement: https://leetcode.com/problems/set-matrix-zeroes/
+
+class Solution {
+public:
+    void setZeroes(vector<vector<int>>& matrix){
+        
+        bool firstRowZero = false;
+        bool firstColumnZero = false;
+        
+        // Get status
+        markZeros(matrix, firstRowZero, firstColumnZero);
+        
+        int row;
+        int col;
+        
+        // change corrosponding cell values
+        for(row = 1; row < matrix.size(); row++){
+            for(col = 1; col < matrix[0].size(); col++){
+                if(matrix[row][0] == 0 || matrix[0][col] == 0)
+                    matrix[row][col] = 0;
+            }
+        }
+        
+        // change 0th row and 0th col if valid
+        if(firstRowZero){
+            for(col = 0; col < matrix[0].size(); col++)
+                matrix[0][col] = 0;
+        }
+        if(firstColumnZero){
+            for(row = 0; row < matrix.size(); row++)
+                matrix[row][0] = 0;
+        }
+    }
+    
+    
+    void markZeros(vector<vector<int>>& matrix, bool& firstRowZero, bool& firstColumnZero){
+        
+        int row;
+        int col;
+        
+        // * get first row and col status before changing status for other cells
+        if(matrix[0][0] == 0){
+            firstRowZero = firstColumnZero = true;
+        }
+        else{
+            for(row = 0; row < matrix[0].size(); row++){
+                if(matrix[0][row] == 0){
+                    firstRowZero = true;
+                    break;
+                }
+            }
+
+            for(col = 0; col < matrix.size(); col++){
+                if(matrix[col][0] == 0){
+                    firstColumnZero = true;
+                    break;
+                }
+            }
+        }
+        
+        // status for other cells
+        for(row = 1; row < matrix.size(); row++){
+            for(col = 1; col < matrix[0].size(); col++){
+                
+                if(matrix[row][col] == 0){
+                    matrix[row][0] = matrix[0][col] = 0;
+                }
+            }
+        }
+    }
+    
+};
+
