77. Validate Configuration Register Layout

#include <stdio.h>

typedef struct {
    unsigned short reg;
} ConfigRegister;

int validate_config(ConfigRegister *cfg) {
    // Write logic using pointer access
    if(!(cfg->reg & 1)){
        //printf("Bit 0 enabled\n");
        return 0;
    }
    else if(!(((cfg->reg >> 2) & 0x03) < 0x03)){
        //printf("Priority valid\n");
        return 0;
    }
    else if(!(((cfg->reg >> 4) & 0x0F) == 0)){
        //printf("Reserved valid\n");
        return 0;
    }
    return 1;
}

int main() {
    ConfigRegister cfg;
    scanf("%hx", &cfg.reg);

    int result = validate_config(&cfg);
    printf("%d", result);

    return 0;
}