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Find the missing number in a sorted array of limited range
• Difficulty Level : Basic
• Last Updated : 29 Apr, 2021

Given a sorted array of size n and given that there are numbers from 1 to n+1 with one missing, the missing number is to be found. It may be assumed that array has distinct elements.
Examples:

```Input : 1 3 4 5 6
Output : 2

Input  : 1 2 3 4 5 7 8 9 10
Output  : 6```

We traverse all elements. For every element a[i], we check if it is equal to i+1 or not. If not, we return (i+1).

## C++

 `// C++ program to find missing Number in``// a sorted array of size n and distinct``// elements.``#include``using` `namespace` `std;` `// Function to find missing number``int` `getMissingNo(``int` `a[], ``int` `n)``{``    ``for` `(``int` `i=0; i

## Java

 `// Java program to find missing Number in``// a sorted array of size n and distinct``// elements.``class` `Main``{``    ``// Function to find missing number``    ``static` `int` `getMissingNo(``int` `a[])``    ``{``        ``int` `n = a.length;``        ``for` `(``int` `i=``0``; i

## Python

 `# Python program to find missing Number in``# a sorted array of size n and distinct``# elements.` `# function to find missing number``def` `getMissingNo(a):``    ``n ``=` `len``(a)``    ` `    ``for` `i ``in` `range``(n):``        ``if``(a[i] !``=` `i ``+` `1``):``            ``return` `i ``+` `1``            ` `    ``# If all numbers from 1 to n``    ``# are present``    ``return` `n``+``1` `# Driver code``a ``=` `[``1``, ``2``, ``4``, ``5``, ``6``]``print``(getMissingNo(a))` `# This code is contributed by Sachin Bisht`

## C#

 `// C# program to find missing Number``// in a sorted array of size n and``// distinct elements.``using` `System;` `class` `GFG``{``    ` `// Function to find missing number``static` `int` `getMissingNo(``int` `[]a, ``int` `n)``{``    ``for` `(``int` `i = 0; i < n; i++)``        ``if` `(a[i] != (i + 1))``            ``return` `(i + 1);` `    ``// If all numbers from``    ``// 1 to n are present``    ``return` `n + 1;``}` `// Driver code``public` `static` `void` `Main()``{``    ``int` `[]a = {1, 2, 4, 5, 6};``    ``int` `n = a.Length;``    ``Console.WriteLine(getMissingNo(a, n));``}``}` `// This code is contributed by ihritik`

## PHP

 ``

## Javascript

 ``

Output :

`3`

Time Complexity: O(n)

Auxiliary Space: O(1)
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