Decimal to Binary

Question

I have a number that I would like to convert to binary (from decimal) in C.

I would like my binary to always be in 5 bits (the decimal will never exceed 31). I alrea

Answer 1

#include 
#include 

char numstr[9024];
int i = 0;

void format(int n, int base);
void printreverse(char *s);

int main()
{
     int testnum = 312;    // some random test number
     format(testnum, 2);   // 2 for binary
     printreverse(numstr);
     putchar('\n');

     return 0;
}

void format(int n, int base)
{
    if (n > 0) {
        char tmp = (n % base) + '0';
        numstr[i++] = tmp;

        // If we put this above other two we don't need printreverse,
        // But then we will have unwanted results in other places of numstr if we can't reset it

        format(n/base, base); 
    } else
        numstr[i] = '\0'; // terminating character
}

void printreverse(char *s)
{
    long len = strlen(s);
    while (len-->0)
        putchar(s[len]);
}