Why it is showing time limit exceeded?

Question

In the following question I am getting time limit exceeded message on whichever compiler I tried(though they were all online compilers).What should be the problem?

#include <stdio.h>
int fact(int);
int main(void)
{
    int num,res;
    printf("enter any number");
    scanf("%d",&num);
    res=fact(num);
    printf("%d",res);
    return 0;
}
int fact(int x)
{
    int ans;
    while(x!=1)
        ans=(x*fact(x-1));
    return ans;
}

Answer 1

Problem is that your fact function never stopped since while loop never ends.

int fact(int x)
{
    int ans;
    while(x!=1)
        ans=(x*fact(x-1)); //X is never changed!
    return ans;
}

Probably you wanted this:

int fact(int x)
{
    int ans = 1; //Set default value for return
    if(x!=1) //Go recursive only if X != 1
        ans=(x*fact(x-1));
    return ans;
}

Answer 2

It is because your fact function goes into infinite loop.

Assuming you are calculating factorial of a number x, this should be the correct fact function.

int fact(int x)
{
    if(x!=1)
        return x*fact(x-1);
    return 1;
}

Answer 3

int fact(int x)
{
    int ans;
    while(x!=1)
        ans=(x*fact(x-1));
    return ans;
}

It is an infinite loop. This is the reason why you get an error as time limit exceeded. Replace the loop to an if condition:

int fact(int x)
{
    int ans = 1;
    if(x!=1)
        ans=(x*fact(x-1));
    return ans;
}