From 21b4200d3d451b72c03c07b9ae9b61fe045f9c47 Mon Sep 17 00:00:00 2001
From: Aahi Awasthee <aahiawasthee@example.com>
Date: Sun, 21 Dec 2025 00:31:19 -0600
Subject: [PATCH] Solved Array Problems

---
 disappearing-numbers.java | 22 +++++++++++++++++
 game-of-life.java         | 51 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 73 insertions(+)
 create mode 100644 disappearing-numbers.java
 create mode 100644 game-of-life.java

diff --git a/disappearing-numbers.java b/disappearing-numbers.java
new file mode 100644
index 00000000..ec3478fc
--- /dev/null
+++ b/disappearing-numbers.java
@@ -0,0 +1,22 @@
+//TC: O(n)
+//SC: O(1)
+
+class Solution {
+    public List<Integer> findDisappearedNumbers(int[] nums) {
+        int n = nums.length;
+        List<Integer> result = new ArrayList<>();
+        for (int i = 0; i < n; i++) {
+            int idx = Math.abs(nums[i]) - 1;
+            if (nums[idx] > 0) {
+                nums[idx] = nums[idx] * -1;
+            }
+        }
+
+        for (int i = 0; i < n; i++) {
+            if(nums[i] > 0){
+                result.add(i+1);
+            }
+        }
+        return result;
+    }
+}
\ No newline at end of file
diff --git a/game-of-life.java b/game-of-life.java
new file mode 100644
index 00000000..866799e0
--- /dev/null
+++ b/game-of-life.java
@@ -0,0 +1,51 @@
+//TC: O(m*n)
+//SC: O(1)
+
+
+class Solution {
+    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 countLive = countLives(board, i, j);
+                if (board[i][j] == 1 && (countLive < 2 || countLive > 3)) {
+                    board[i][j] = 2;
+                }
+                if (board[i][j] == 0 && countLive == 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;
+                } else if (board[i][j] == 3) {
+                    board[i][j] = 1;
+                }
+            }
+        }
+
+    }
+
+    private int countLives(int[][] board, int i, int j) {
+        int count = 0;
+        //r, b, l, t, tr,br,bl,tl
+        int[][] dirs = new int[][] { { 0, 1 }, { 1, 0 }, { 0, -1 }, { -1, 0 }, { -1, 1 }, { 1, 1 }, { 1, -1 },
+                { -1, -1 } };
+
+        for (int[] dir : dirs) {
+            int nr = i + dir[0];
+            int nc = j + dir[1];
+
+            //bounds check
+            if(nr >= 0 && nr < board.length && nc >=0 && nc < board[0].length && (board[nr][nc] == 1 || board[nr][nc] == 2)) {
+                count++;
+            }
+        }
+        return count;
+    }
+}
\ No newline at end of file