Completed Array-2

disappearednumbers.cpp

@@ -0,0 +1,22 @@
+class Solution {
+public:
+    vector<int> findDisappearedNumbers(vector<int>& nums) {
+        vector<int> result;// array to store the missing numbers
+        int n = nums.size();
+        for(int i = 0 ; i < n ; i++){
+            int index  = abs(nums[i]) - 1; // get the index corresponding to the current number
+            if(nums[index] > 0){
+                nums[index] *= -1;//if +ve make it -ve
+            }
+        }
+        for(int i = 0 ; i < n ; i++){
+            if(nums[i]>0){
+                result.push_back(i+1);//if +ve add to the result array 
+            }else{
+                nums[i] *= -1;//restores the values back to +ve
+            }
+        }
+        return result;
+
+    }
+};

gameoflife.cpp

@@ -0,0 +1,54 @@
+class Solution {
+public:
+    void gameOfLife(vector<vector<int>>& board) {
+        int m = board.size();
+        int n = board[0].size();
+
+        for(int i = 0 ; i < m ; i++){
+            for(int j = 0 ; j < n ; j++){
+                int count = countalive(board,i,j);
+
+                if((board[i][j] == 1) && (count < 2 || count > 3)){
+                    board[i][j] = 2;
+                }
+                if((board[i][j] == 0) && (count == 3)){
+                    board[i][j] = 3;
+                }
+            }
+        }
+
+        for(int i = 0 ; i < m ; i++){
+            for(int j = 0 ; j < n ; j++){
+                if(board[i][j] == 2){
+                    board[i][j] = 0;
+                }
+                if(board[i][j] == 3){
+                    board[i][j] = 1;
+                }
+            }
+        }
+    }
+
+private :
+    int countalive(vector<vector<int>>& board,int i,int j){
+        int count = 0;
+
+
+        vector<vector<int>> direction = {
+            {0,-1},{-1,0},{1,0},
+            {-1,-1},{-1,1},{1,-1},{1,1},{0,1}
+        };
+
+        for(auto &dir : direction){
+            int nrow = i + dir[0];
+            int ncolumn = j + dir[1];
+
+            if(nrow >= 0 && ncolumn >= 0 &&
+               nrow < board.size() && ncolumn < board[0].size() &&
+               (board[nrow][ncolumn] == 1 || board[nrow][ncolumn] == 2)){
+                count++;
+            }
+        }
+        return count;
+    }
+};