why is this c program giving runtime error [closed]

Answer 1

declaration of array caused the runtime error please refer to this http://www.tutorialspoint.com/cprogramming/c_arrays.htm

Answer 2

Your mistake is this: int a[m]

What you expect to be value of m? Change to a[256]. Or define int *a then after scanning m: a = malloc( m * sizeof (int) ).

Answer 3

in your code

a[m]

is erroneous. value of m is used as uninitialized.

To solve your issue, you can use dynamic memory allocation for a variable int * a based on the user input of m.

Note:

1. Always initialize your local variables.
2. Check the return value of scanf() for successful input.
3. [A request] C ignores white-spaces [mostly]. Use them to make your code more human-readable.

Answer 4

If you want

a[m];

From C99 you have VLA

int m;
scanf("%d",&m);
int a[m];

Because I see in your code you are trying to scan the size of the array.

Alternatively you can have a dynamic array

int *a = malloc(sizeof(int) * m);

@Sourav has already mentioned the reason for crash.

The value of m is undeterminate.