Create MissingNumber.js

Chandanmali · web-flow · commit 690420b72275 · 2023-10-07T12:08:33.000+05:30
diff --git a/Data-Structures/Array/MissingNumber.js b/Data-Structures/Array/MissingNumber.js
@@ -0,0 +1,37 @@
+/**
+ * [MissingNumber](https://www.geeksforgeeks.org/find-the-missing-number/) is an algorithm to find missing number in array.
+ *
+ * Notes:
+ * The numbers will be in the range (1, N), an array of size N can be maintained to keep record of the elements present in the given array
+ *
+ * @complexity: O(log(n)) (on average )
+ * @complexity: O(log(n)) (worst case)
+ * @flow
+ */
+
+// Function to find the missing number
+function findMissing(arr,N){
+let i;
+let const = [];
+for (i = 0; i <= N; i++) {
+			const[i] = 0;
+		}
+
+		for (i = 0; i < N; i++) {
+			const[arr[i] - 1] = 1;
+		}
+
+		let ans = 0;
+		for (i = 0; i <= N; i++) {
+			if (const[i] == 0)
+				ans = i + 1;
+		}
+		console.log(ans);
+}
+
+// Driver code
+		let arr = [ 1, 3, 7, 5, 6, 2 ];
+		let n = arr.length;
+
+		// Function call
+	findMissing(arr,n);
