77. Validate Configuration Register Layout

#include <stdio.h>

typedef struct {
    unsigned short reg;
} ConfigRegister;
typedef union {
    struct {
        unsigned char enable: 1;
        unsigned char mode: 1;
        unsigned char priority: 2;
        unsigned short reserved: 12;
    };
    unsigned short reg;
} UnionRegister;
int validate_config(ConfigRegister *cfg) {
    // Write logic using pointer access
    UnionRegister reg1;
    reg1.reg = cfg->reg;
    if ((reg1.enable == 1) && (reg1.priority != 3) && (reg1.reserved == 0)) return 1;
    return 0;
}

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

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

    return 0;
}