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 reg1;
    reg1 = cfg->reg;

    if(!(reg1 & 0x01)) //case1
    return 0;

    if(((reg1>>2) & 0x011) == 0x011) //case 2
    return 0;

    if((reg1>>4) & 0xFFF) //case 3
    return 0;

    return 1;
}

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

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

    return 0;
}