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 val = cfg->reg;
    
    unsigned short enable = val & 0x0001;
    unsigned short priority = (val >> 2) & 0x3;
    unsigned short reversed = val & 0xFFF0;
    if (enable == 0) return 0;
    if (priority == 3) return 0;
    if (reversed != 0) return 0;
    return 1;
}

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

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

    return 0;
}