31. Rotate Left in an 8-bit Register

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

uint8_t rotate_left(uint8_t reg, uint8_t n) {
    
    uint8_t mask = 0;
    for ( uint8_t i = 0 ; i < n ; i++ )
    {
        mask |= ( 1 << 7-i);
    }
    mask &= reg;


    reg <<= n ;

    //printf( " \n  ** %d %d  **" , reg, mask);

    return reg | (mask >> ( 8 - n));
}

int main() {
    uint8_t reg, n;
    scanf("%hhu %hhu", &reg, &n);
    printf("%u", rotate_left(reg, n));
    return 0;
}