solution of All missing number added

Author: MohammedHassan07

LeetCode/AllMissingNumber.java

@@ -0,0 +1,50 @@
+import java.util.ArrayList;
+
+public class AllMissingNumber {                 // Question: Find all missing number in the array in O(log n) timeComplexity
+    public static void main(String[] args) {
+
+        int[] arr = {2, 1, 3, 6, 4, 9, 5, 3, 2};
+
+        System.out.println(missingNumber(arr));
+    }
+
+    // method to sort the array using cyclic sort and to find missing number
+    public static ArrayList<Integer> missingNumber(int[] arr) {     // Here we use ArrayList because we don`t know how many numbers are missing
+
+        int i = 0;
+        while (i < arr.length) {
+
+            int index = arr[i] - 1;
+
+            if(arr[i] != arr[index]) {
+
+                swap(arr, i, index);
+            }else {
+
+                i++;
+            }
+        }
+
+        // Finding missing number
+        ArrayList<Integer> nums = new ArrayList<>();
+        for (int j = 0; j < arr.length; j++) {
+
+            if(arr[j] != j + 1) {
+
+                nums.add(j + 1);        // Adding the numbers into the list
+            }else {
+
+                j++;
+            }
+        }
+        return nums;
+    }
+
+    // Method to swap the numbers
+    public static void swap(int[] arr, int first, int second) {
+
+        int temp = arr[first];
+        arr[first] = arr[second];
+        arr[second] = temp;
+    }
+}