77. Validate Configuration Register Layout

#include <stdio.h>

typedef struct {
    unsigned short reg;
} ConfigRegister;

int validate_config(ConfigRegister *cfg) {
    int enable = cfg->reg & 1U;
    int priority = (cfg->reg >> 2) & 0x03;
    int reserv = (cfg->reg >> 4) & 0xFFF;
    if (enable == 1 && priority != 3 && reserv == 0)
        return 1;
    return 0;
}

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

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

    return 0;
}