Array 2 Completed

DisappearedNumbers1.java

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+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * url: https://leetcode.com/problems/find-all-numbers-disappeared-in-an-array/
+ * Title: 448. Find All Numbers Disappeared in an Array Time Complexity:
+ * O(n) Space Complexity: O(1)
+ */
+public class DisappearedNumbers1 {
+
+    public List<Integer> findDisappearedNumbers(int[] nums) {
+        List<Integer> mList = new ArrayList<>();
+        for (int i = 0; i < nums.length; i++) {
+            int pos = Math.abs(nums[i]) - 1;
+            if (nums[pos] > 0) {
+                nums[pos] = -nums[pos];
+            } 
+        }
+        for (int i = 0; i < nums.length; i++) {
+            if (nums[i] > 0) {
+                mList.add(i + 1);
+        }
+        }   
+        return mList;
+    }
+
+    public static void main(String[] args) {
+        List<Integer> missing = new DisappearedNumbers1().findDisappearedNumbers(new int[]{4, 3, 2, 7, 8, 2, 3, 1});
+        System.out.println(missing);
+
+        missing = new DisappearedNumbers1().findDisappearedNumbers(new int[]{10,2,5,10,9,1,1,4,3,7});
+        System.out.println(missing);
+    }
+}

GameOfLife.java

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+/**
+ * url: https://leetcode.com/problems/game-of-life/
+ * Title: 289. Game of Life
+ * Time Complexity: O(m*n)
+ * Space Complexity: O(1)
+ */
+public class GameOfLife {
+
+    int moves[][] = {{0, 1}, {0, -1}, {1, 0,}, {-1, 0}, {-1, -1}, {-1, 1}, {1, -1}, {1, 1}};
+    // moves in all eight directions.
+
+    public void gameOfLife(int[][] board) {
+        int m = board.length;
+        int n = board[0].length;
+
+        for (int i = 0; i < m; i++) {
+            for (int j = 0; j < n; j++) {
+                int alivecount = 0;
+                for (int[] move : moves) {
+                    int x = i + move[0];
+                    int y = j + move[1];
+                    if (x >= 0 && x < m && y >= 0 && y < n) {
+                        if (board[x][y] == 1 || board[x][y] == 2) { // 2 for mar gaya but alive in original state
+                            alivecount++;
+                        }
+                    }
+                }
+                if (board[i][j] == 1 || board[i][j] == 3) {
+                    if (alivecount > 3) { // overpopulation
+                        board[i][j] = 2; // 2 for mar gaya
+                    }
+                    if (alivecount < 2) { // underpopulation
+                        board[i][j] = 2; // 2 for mar gaya
+                    }
+                    if (alivecount == 2 || alivecount == 3) { // underpopulation
+                        board[i][j] = 1; // alive
+                    }
+                }
+                if (board[i][j] == 0) {
+                    if (alivecount == 3) {
+                        board[i][j] = 3; // 3 for new born
+                    }
+                }
+
+            }
+        }
+    }
+
+    public static void main(String[] args) {
+            int[][] board = {{0, 1, 0}, {0, 0, 1}, {1, 1, 1}, {0, 0, 0}};
+            new GameOfLife().gameOfLife(board);
+             for (int i = 0; i < board.length; i++) {
+                for (int j = 0; j < board[0].length; j++) {
+                    if (board[i][j] == 2) {
+                        board[i][j] = 0;
+                    }
+                    if (board[i][j] == 3) {
+                        board[i][j] = 1;
+                    }
+                }
+            }
+             for (int i = 0; i < board.length; i++) {
+                for (int j = 0; j < board[0].length; j++) {
+                    System.out.print(board[i][j] + " ");
+                }
+                System.out.println();
+            }
+    }
+}