77. Validate Configuration Register Layout

#include <stdio.h>

typedef struct {
    unsigned short reg;
} ConfigRegister;

int validate_config(ConfigRegister *cfg) {
    if (!((cfg->reg >> 0) & 1))
        return 0;

    int priority = (cfg->reg >> 2) & 0b11;
    if (priority == 0b11)
        return 0;
    if ((cfg->reg >> 4) != 0)
        return 0;

    return 1; 
}

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

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

    return 0;
}