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))==1)
    {
        if((((cfg->reg)>>(0x0001))& (((0x0001)<<(0x0002))-(0x0001)))==(0x0003))
            return (0x0000);
        else
        {    if(((cfg->reg)&(~((1<<4)-1)))>>4 == 0)
                return (0x0001);
            else
                return (0x0000);
        }
    }
    return 0;
}

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

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

    return 0;
}