77. Validate Configuration Register Layout

#include <stdio.h>

typedef struct {
    unsigned short reg;
} ConfigRegister;

int validate_config(ConfigRegister *cfg) {
    // Write logic using pointer access
    int flag = 0;
    if(((cfg->reg & 1) == 1) && (cfg->reg & (1 << 2) != 1)
    && (cfg->reg & (1 << 3) != 1)) {
        for (int i = 4; i < 16; i++) {
            if ((cfg->reg  & (1 << i)) == 0) {
                flag++;
            }  
        }
        if (flag == 12) {return 1;}
    }
    return 0;
}

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

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

    return 0;
}