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(base == 2) {
        // BIN
        int flag = 0;
        for(int i = 7; i >= 0 ; i--) {
            int digit = (num >> i) & 1;
            if(digit == 1) flag = 1;
            if(flag) printf("%d", digit);
        }
        if (!flag) printf("%d", 0);
    } else {
        // HEX
        int flag = 0;
        for(int i = 3; i >= 0 ; i--) {
            uint8_t digit = (num >> (i * 4)) & 0xF;
            if(digit) flag = 1;
            if(flag) {
                char hex_digit = (digit < 10) ? ('0' + digit) : ('A' + digit - 10);
                printf("%c", hex_digit);
            }
        }
        if (!flag) printf("%d", 0);
    }
}

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

    print_base(num, base);
    return 0;
}

Solving Approach