67. Control Register Using Nested Bitfields

#include <stdio.h>

typedef union {
    unsigned char reg;
    struct {
        unsigned char enable : 1;
        unsigned char mode : 1;
        unsigned char priority : 2;
        unsigned char reserved : 4;
    } bits;
} ControlRegister;

// Write your logic here
int validate_register(ControlRegister ctrl) {
    if(ctrl.bits.enable && (ctrl.bits.priority <=2) && ((ctrl.bits.reserved)==0)) return 1;
    return 0;
}

int main() {
    ControlRegister ctrl;
    scanf("%hhx", &ctrl.reg);

    int result = validate_register(ctrl);
    printf("%d", result);

    return 0;
}