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) {
   int l=num>=128?8:4;
   if(num==0) {
    printf("0");
    return;
   }
    if(base==2){
        
        for(int i=l-1;i>=0;i--){
            if(num&(1<<i)){
                printf("1");
            }
            else printf("0");
        }
    }
    else{
        int i=0,c=0;
        char str[5];
        while(num){
            int r=num%16;
            if(r>9){
                str[c++]=r+('A'-10);
            }
            else{
                str[c++]=r+'0';
            }
            num=num/16;
        }
        for(int i=c-1;i>=0;i--){
            printf("%c",str[i]);
        }
    }
}

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

    print_base(num, base);
    return 0;
}

Solving Approach