c - Undesired output with modulo operator and ' pow '

Question

for the below shown code

#include<stdio.h>
#include<math.h>
int main()
{
    int a,i,n=0;
    int temp=0;
    scanf("%d",&a);
    //for number of digits
    while(temp>=0)
    {
        n++;
        temp = a / pow(10,n);
        if(temp==0)
            break;
    }
    printf("%d
",n);
    for (i=1;i<=n;i++)
    {
        temp = a % (int)pow(10,i);
        printf("%d
",temp);
    }
    return 0;
}

the output is (input is 123)

123
3
3
24
123

Image of the output given by gcc

so the question is why 24 is coming instead of 23 ?

please check the image because the output given by online compiler(ideone) is 23. Only the output by gcc has 24

Answer 1

I see the following errors:

while(temp>=0)

but temp is not initialized.

temp = a / pow(10,n);

but temp is integer and the calculation is double. You loose precision, which is the probable cause of your wrong output.