19. Extract a Bit Field from a 32-bit Register

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

uint32_t extract_field(uint32_t reg, uint8_t pos, uint8_t len) {
    uint32_t result = (reg >> pos) & ((1U << len) - 1);
    return result;
    
}

int main() {
    uint32_t reg;
    uint8_t pos, len;
    scanf("%u %hhu %hhu", &reg, &pos, &len);
    printf("%u", extract_field(reg, pos, len));
    return 0;
}

/*
     7 5
1101 1100 0001
           110

        0111
0000 0000 1000
0000 0000 0001
---------------
              1

*/