VS2015 中使用freopen_s

#include "stdafx.h"
#include <stdio.h>
#include <stdlib.h>
#include <iostream>
using namespace std;



int main(){
    FILE *stream1, *stream2;
    fopen_s(&stream1, "input.txt", "r"); 
    fopen_s(&stream2, "output.txt", "w");

    int n;
    fscanf_s(stream1, "%d", &n);//从stream1中读取一个int
    fprintf(stream2, "%d", n);  //将int输出到stream2

    fclose(stream1);
    fclose(stream2);
    return 0;
}