graphs/piscine/my_itoa/my_itoa.c


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#include "my_itoa.h"

char *my_itoa(int value, char *s)
{
    if (value == 0)
    {
        s[0] = '0';
        s[1] = '\0';
        return s;
    }
    char *head = s;
    if (value < 0)
    {
        s[0] = '-';
        s++;
        value = -value;
    }

    // count numbers
    int t = value;
    int n = 0;
    while (t > 0)
    {
        t /= 10;
        n++;
    }

    // n = number count
    s[n] = '\0';
    n--;
    for (; n >= 0; n--)
    {
        s[n] = value % 10 + '0';
        value /= 10;
    }

    return head;
}