77. Validate Configuration Register Layout

#include <stdio.h>

typedef struct {
    unsigned short reg;
} ConfigRegister;

int validate_config(ConfigRegister *cfg) {
    // Write logic using pointer access
    if((cfg->reg & 0x0001)==0) return 0;
    unsigned short val = (cfg->reg>>2) & 0x03;
    if(val==0x03) return 0;
    if((cfg->reg & 0xFFF0)!=0) return 0;
    return 1;
}

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

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

    return 0;
}