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 bm = ((1<<n)-1)<<(8-n);
    bm = reg & bm;
    reg = reg << n;
    bm = bm >> (8-n);
    reg = reg | bm;
    return reg;         #OR simply return (reg<<n) | (reg>>(8-n));
}

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