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
    if(num==0){
        printf("0");
        return;
    }
    char binary[16],d=0;
    if(base==2){
        d=2;
    }else if(base==16){
        d=16;
    }
    int r,i;
    while(num>0){
        r= num%d;
        if(r>=10){
            r=r+55;
             binary[i]=(char)r;
        }else
        binary[i]='0'+r;
        num=num/d;
        i++;
       
    }
    for(int j=i-1;j>=0;j--){
        printf("%c",binary[j]);
    }
}

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

    print_base(num, base);
    return 0;
}

Solving Approach