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) & 1) == 0) {
        return 0;
    }
    if (((cfg->reg & 100) == 100) && ((cfg->reg & 1000)) == 1000) {
        return 0;
    }

    if ((cfg->reg >> 4) != 0) {
        return 0;
    }
    return 1;
}

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

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

    return 0;
}