Merge pull request codeharborhub#2932 from Ishitamukherjee2004/main

Solution of 268 (LC No.) is added

Author: ajay-dhangar

dsa-solutions/lc-solutions/0200-0299/0268-Missing-Number.md

@@ -0,0 +1,67 @@
+---
+id: missing-number
+title: Missing Number
+sidebar_label: 268-Missing-Number
+tags:
+  - Array
+  - Hash Table
+  - Math
+  - Binary search
+  - Bit Manupulation
+  - Sorting
+
+---
+
+## Problem Description
+
+Given an array `nums` containing `n` distinct numbers in the range `[0, n]`, return the only number in the range that is missing from the array.
+
+
+### Example
+
+**Example 1:**
+
+```
+Input: nums = [3,0,1]
+Output: 2
+Explanation: n = 3 since there are 3 numbers, so all numbers are in the range [0,3]. 2 is the missing number in the range since it does not appear in nums.
+```
+
+**Example 2:**
+```
+Input: nums = [0,1]
+Output: 2
+Explanation: n = 2 since there are 2 numbers, so all numbers are in the range [0,2]. 2 is the missing number in the range since it does not appear in nums.
+```
+
+### Constraints
+
+- `1 <= n <= 104`
+
+## Solution Approach
+
+### Intuition:
+
+To efficiently determine the missing number in the array
+
+
+## Solution Implementation
+
+### Code (C++):
+
+```cpp
+class Solution {
+public:
+    int missingNumber(vector<int>& nums) {
+        int n = nums.size();
+        int sum = (n*(n+1))/2;
+        int s1=0;
+        for(int i=0; i<n; i++){
+             s1+=nums[i];
+        }
+        int ans = sum-s1;
+        return ans;
+    }
+};
+
+```