Merge pull request #87 from jahnvisrivastava100/patch-1

Create Set Matrix Zero

Author: smv1999

2D Arrays/Set Matrix Zero.cpp

@@ -0,0 +1,55 @@
+/*______________________________________________________________________PROBLEM___________________________________________________________*/
+
+/*Given an m x n matrix. If an element is 0, set its entire row and column to 0. Do it in-place.
+   Follow up:
+
+A straight forward solution using O(mn) space is probably a bad idea.
+A simple improvement uses O(m + n) space, but still not the best solution.
+Could you devise a constant space solution?
+
+ EXAMPLE 1:
+ Input: matrix = [[1,1,1],[1,0,1],[1,1,1]]
+ Output: [[1,0,1],[0,0,0],[1,0,1]]
+ 
+ EXAMPLE 2:
+ Input: matrix = [[0,1,2,0],[3,4,5,2],[1,3,1,5]]
+ Output: [[0,0,0,0],[0,4,5,0],[0,3,1,0]]
+ 
+ 
+ 
+ Constraints:
+
+m == matrix.length
+n == matrix[0].length
+1 <= m, n <= 200
+-231 <= matrix[i][j] <= 231 - 1
+*/
+ 
+
+class Solution {
+public:
+    void setZeroes(vector<vector<int>>& m) {
+        set<int>row,col;
+        
+      for(int i=0;i<m.size();i++){
+          for(int j=0;j<m[0].size();j++){
+              if(m[i][j]==0){
+                  row.insert(i);
+                  col.insert(j);
+              }
+          }
+      }
+    
+    
+        for(auto it=row.begin();it!=row.end();it++){
+            for(int j=0;j<m[0].size();j++){
+                m[*it][j]=0;
+            }
+            
+        }
+        for(auto it=col.begin();it!=col.end();it++){
+            for(int j=0;j<m.size();j++){
+                m[j][*it]=0;
+            }
+        }
+    }