Convert Integer to Hex String Without sprintf or itoa functions

Code

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

void print_hex(uint16_t num) {
    char hex[5];   // max 4 hex digits + null terminator
    int i = 0;

    if (num == 0) {
        putchar('0');
        return;
    }

    while (num > 0) {
        uint8_t digit = num & 0xF;   // extract last 4 bits (hex digit)

        if (digit < 10)
            hex[i++] = '0' + digit;
        else
            hex[i++] = 'A' + (digit - 10);

        num >>= 4;   // move to next nibble
    }

    // print in reverse order
    while (i > 0) {
        putchar(hex[--i]);
    }
}
int main() {
    uint16_t num;
    scanf("%hu", &num);
    print_hex(num);
    return 0;
}

Solving Approach