Convert Integer to Hex String Without sprintf or itoa functions

Code

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

void print_hex(uint16_t num) {
    // Your logic here
    if (num == 0) printf("0");
    char ans[4];
    int8_t idx = 3;
    while (num > 0) {
        uint8_t val = (num&0xF);
        if (val > 9) {
            ans[idx--] = (char)'A'+val-10;
        } else {
            ans[idx--] = (char)'0'+val;
        }
        num >>= 4;
    }
    for (int8_t i = idx+1; i < 4; i++) {
        printf("%c", ans[i]);
    }
}

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

Solving Approach