77. Validate Configuration Register Layout

#include <stdio.h>

typedef struct {
    unsigned short reg;
} ConfigRegister;

int validate_config(ConfigRegister *cfg) {
    // Write logic using pointer access
    unsigned short reg = cfg->reg;

    int enable = (reg & 0x1) == 1;
    int priority_ok = ((reg >> 2) & 0x3) != 3;
    int reserved_ok = (reg & 0xFFF0) == 0;

    return (enable && priority_ok && reserved_ok) ? 1 : 0;
}

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

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

    return 0;
}