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))
        return 0;
    if (((cfg->reg)>>2 & 3) == 3)
        return 0;
    if ((cfg->reg >> 4 & (1<<13)-1))
        return 0;

    return 1;
}

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

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

    return 0;
}