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

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

int main() {
    uint32_t reg;
    int pos, len;

    scanf("%u", &reg);   // 32-bit register
    scanf("%d", &pos);   // start position
    scanf("%d", &len);   // number of bits

    uint32_t result = (reg >> pos) & ((1U << len) - 1);

    printf("%u", result);
    return 0;
}