Convert Integer to Hex String Without sprintf or itoa functions

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

void print_hex(uint16_t num) {
    // Your logic here

    if(num == 0){
        printf("0");
        return;
    }

    uint16_t mask = 0xF000;
    int counter = 0;

    while((mask&num) == 0){
        mask = mask >> 4;
        counter ++;
    }

    for(int i = counter; i<4; i++){
        uint16_t val = mask & num;
        val = val >>( 3-counter)*4;
        
        
        if(val <= 9){
            printf("%d", val);
        }else{
            // printf("val: %d\n", val);
            printf("%c", ('A'+(val-10)));
        }

        mask = mask >> 4;
        counter++;
    }


}

int main() {
    uint16_t num;
    scanf("%hu", &num);
    print_hex(num);
    return 0;
}