31. Rotate Left in an 8-bit Register

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

uint8_t rotate_left(uint8_t reg, uint8_t n) {
    // Your code here
	uint8_t mask = ((1 << (n+1)) - 1);
    uint8_t ext_bits = reg & (mask << (8 - n));
    ext_bits >>= (8 - n);
    reg <<= n;
    reg |= ext_bits;
    return reg;
}


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