int_to_bin_str

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

char* to_bin_str(int num)
{
    char temp[2];
    char bin_str[33] = {0};
    int shifts = 31;
    int bit;

    temp[1] = '\0';

    while(shifts >= 0)
    {
        bit = num & (1 << shifts);
        shifts--;

        temp[0] = (bit != 0) + '0';
        strcat(bin_str, temp);
    }

    return strdup(bin_str);
}

int main()
{
    int num = 0;
    char* bin_str = NULL;

    scanf("%d", &num);

    bin_str = to_bin_str(num);
    printf("%s\n", bin_str);

    free(bin_str);

    return 0;
}