Control Register Using Nested Bitfields

Code

#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) {

    unsigned char enable_comp = ctrl->bits.enable;
    unsigned char priority_comp = ctrl->bits.priority;
    unsigned char reserved_comp = ctrl->bits.reserved;

    if((enable_comp == 1) &&(priority_comp <= 2)&&(reserved_comp == 0)){
        return 1;
    }else{
        return 0;
    }
    
}

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

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

    return 0;
}

Solving Approach