C++随机数生成以及文件数据读取

#include<ctime>#include<cstdio>#include<iostream>#include<cmath>#include<cstring>#include<cstdlib>using namespace std;int main(){   freopen("in.txt","r",stdin);     //从in.txt 中读入数据   freopen("out.txt","w",stdout);   srand(time(0));   cout<<rand()%100+1<<endl;   fclose(stdin);   fclose(stdout);}