#include <iostream>
#include <cstring>
using namespace std;

int main(void){
	FILE *arq;
	double aux[]= {4, 2, 6};
	arq = fopen("teste.txt", "w+b");
	if(arq == NULL){
		cout << "Erro";
		exit(1);
	}
	fwrite(&aux, sizeof(double), 3, arq);
	fclose(arq);
}