实验六

1

合并文件，添加语句

#include
#include
#include
#include
using namespace std;
int main(){
string filename;
cout << "输入打开的文件: ";
cin >> filename;
ofstream fout;
fout.open(filename,ios_base::app);
if(!fout.is_open()){
cerr << "fail to open " << filename << endl;
system("pause");
exit(0);
}
fout << endl << "merge successfully" << endl;
return 0;
}

 

2

main.cpp

#include
#include
#include
#include
#include
#include
#include "utils.h"
using namespace std;
int main() {
ifstream fin;
ofstream fout;
string filename1;
int num, totalline = 0;
cout << "输入名单列表文件名：";
cin >> filename1;
cout << "输入随机抽点人数：";
cin >> num;
fin.open(filename1, ios_base::in);
if (!fin.is_open()) { 
cerr << "fail to open file " << filename1 << endl;
system("pause");
exit(0);
}
string temp;
string a[100]; 
if (fin) {
while (getline(fin, temp)) {
a[totalline++] = temp; 
}
fin.close();

} 
string filename;
filename = getCurrentDate()+".txt";
cout << "new file name is "<srand(std::time(0));
for (int i = 0;i < num;i++) {

int line;
int random = rand();
line = rand()%totalline ;
cout << a[line] << endl;
fout.open(filename, ios_base::app);
fout << a[line] << endl;
fout.close();

}
system("pause"); 
return 0;
}

utils.h

//这个头文件里包含了可用工具函数的声明

#include
using std::string;

// 函数声明
// 返回当前系统时间，格式诸如20190607
string getCurrentDate();

 

utils.cpp

#include "utils.h"
#include
using std::string;

const int SIZE = 20;

// 函数功能描述：返回当前系统时间
// 参数描述：无参数
// 返回值描述：以string类型返回系统当前日期，格式诸如20190611
string getCurrentDate() {

time_t time_seconds = time(0);
struct tm now_time;
localtime_s(&now_time, &time_seconds); // 使用了更安全的localtime_s()

char date[SIZE];

strftime(date, SIZE, "%Y%m%d", &now_time);

return (string(date));
}

 

 

 

 

总结 

挺难的,后面修改了一下，时间可能有问题。