﻿ C Program: Find the missing number from a given array - w3resource

# C Exercises: Find the missing number from a given array

## C Array: Exercise-36 with Solution

Write a program in C to find the missing number in a given array. There are no duplicates in the list.

Pictorial Presentation:

Sample Solution:

C Code:

``````#include <stdio.h>

int pickMissNumber(int *arr1, int ar_size)
{
int i, sum = 0, n = ar_size + 1;
for(i = 0; i < ar_size; i++)
{
sum = sum + arr1[i];
}

return (n*(n+1))/2 - sum;
}

int main()
{
int i;
int arr1[] = {1, 3, 4, 2, 5, 6, 9, 8};

int ctr = sizeof(arr1)/sizeof(arr1[0]);
printf("The given array is :  ");

for(i = 0; i < ctr; i++)
{
printf("%d  ", arr1[i]);
}
printf("\n");

printf("The missing number is : %d \n", pickMissNumber(arr1, ctr));
return 0;
}
```
```

Sample Output:

```The given array is :  1  3  4  2  5  6  9  8
The missing number is : 7
```

Flowchart :

C Programming Code Editor:

Improve this sample solution and post your code through Disqus.

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.

﻿

## C Programming: Tips of the Day

C Programming - What is the argument for printf that formats a long?

Put an l (lowercased letter L) directly before the specifier.

```unsigned long n;
long m;

printf("%lu %ld", n, m);
```

Ref : https://bit.ly/3dIwfkP