77. Validate Configuration Register Layout

#include <stdio.h>

typedef struct {
    unsigned short reg;
} ConfigRegister;

int validate_config(ConfigRegister *cfg) {
    if(((cfg->reg >>0) & 0x1) != 1)
        return 0;
    if(((cfg->reg >>2 )& 0x3) > 2 )
        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;
}