Convert Decimal Number to Binary or Hex Without itoa function

Code

#include <stdio.h>
#include <stdint.h>

void print_base(uint16_t num, uint8_t base) {
    // Your logic here
    bool first_bit=0;
    if(num==0)
            {
                printf("%d",0);
                return;
            }
    if(base==2)
    {
        for(int i=15; i>=0; i--)
        {
            
            if((num >>i)&1)
            first_bit=1;

            if(first_bit)
            {
                printf("%d",(num >>i)&1);
            }
            
            
        }
    }
    else
    {
        int i=0;
        char hex[20];
        char temp;
       while(num!=0)
       {
        temp= num%16;
        hex[i++] = (temp<10)? (temp+'0') : (temp + 'A'- 10);
        num/=16;
       }
        for (int j = i - 1; j >= 0; j--)
        printf("%c", hex[j]);
    }
}

int main() {
    uint16_t num;
    uint8_t base;
    scanf("%hu %hhu", &num, &base);

    print_base(num, base);
    return 0;
}

Solving Approach