struct div_t { int quot; int rem; };

struct div_t { int rem; int quot; };

struct ldiv_t { long quot; long rem; };

struct ldiv_t { long rem; long quot; };

struct lldiv_t { long long quot; long long rem; };

struct lldiv_t { long long rem; long long quot; };

struct imaxdiv_t { intmax_t quot; intmax_t rem; };

struct imaxdiv_t { intmax_t rem; intmax_t quot; };

#include <stdio.h>
#include <math.h>
#include <stdlib.h>
 
// فقط للتوضيح. احذر: لا يتم التأكد من عدم حدوث
// overflow
void itoa(int n, int base, char* buf)
{
 div_t dv = {.quot = n};
 char* p = buf;
 do {
 dv = div(dv.quot, base);
 *p++ = "0123456789abcdef"[abs(dv.rem)];
 } while(dv.quot);
 if(n<0) *p++ = '-';
 *p-- = '0円';
 while(buf < p) { char c = *p; *p-- = *buf; *buf++ = c; } // عكس
}
 
int main(void)
{
 char buf[100];
 itoa(12346, 10, buf);
 printf("%s\n", buf);
 itoa(-12346, 10, buf);
 printf("%s\n", buf);
 itoa(65535, 16, buf);
 printf("%s\n", buf);
}

12346
-12346
ffff