Validate Configuration Register Layout

Code

#include <stdio.h>

typedef struct {
    unsigned short reg;
} ConfigRegister;

int validate_config(ConfigRegister *cfg) {
    
    if(!(cfg->reg&1)) return 0;
    unsigned short p=((cfg->reg>>2)&0x3);
    if (p==3) return 0;

    if(cfg->reg&0xfff0) return 0;


    return 1;
}

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

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

    return 0;
}

Solving Approach