27. Extract Bit Field from 16-bit Register

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

#define START_BIT 	4
#define END_BIT		8
#define BITS_LEN	5		

uint8_t extract_field(uint16_t reg) {
    // Your logic here
    uint16_t mask = ((1 << BITS_LEN) - 1) << START_BIT;

    uint8_t ext_bit = (reg & mask) >> START_BIT;

    return ext_bit;
}

int main() {
    uint16_t reg;
    scanf("%hx", &reg);
    printf("%u", extract_field(reg));
    return 0;
}