Convert Integer to Hex String Without sprintf or itoa functions

Code

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

void print_hex(uint16_t num) {
    char str[4];
    int i=0,v=0;
    if(num==0) 
    {
        printf("0");
        return;
    }
    for(int i=0;i<4;i++){
        v=(num>>(12-4*i))&0x0F;
       // printf("v=%d ",v);
        if(v==0) continue;
        char k=(v>9)?7:0;
        str[i]=(k+v)+'0';
        printf("%C",str[i]);
        v=0;
    }

}

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

Solving Approach