实验六

àì夳堔傛蜴生んèń 2022-01-07 19:49 289阅读 0赞

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#include <iostream>
    #include <fstream>   
    #include <cstring>
    #include <cstdlib>
    using namespace std;
    
    int main() {
        string filename1, filename2, newfilename;
        
        cout << "输入要合并的两个文件名: " ;
        cin >> filename1 >> filename2;
        cout << "输入合并后新文件名: " ;
        cin >> newfilename;
        
        ofstream fout;        // 输出文件流对象 
        ifstream fin;        // 输入文件流对象 
        
        
        fin.open(filename1);  // 将输入文件流对象fin与文件filename1建立关联 
        if(!fin.is_open()) {  // 如果打开文件失败，则输出错误提示信息并退出 
            cerr << "fail to open file " << filename1 << endl;
            exit(0);    
        }
        
        fout.open(newfilename);    // 将输出文件流对象fout与文件newfilename建立关联 
        if(!fin.is_open()) {  // 如果创建/打开文件失败，输出错误提示信息并退出  
            cerr << "fail to open file " << newfilename << endl;
            exit(0);
        }
        
        char ch;
        
        // 从文件输入流对象fin中获取字符，并将其插入到文件输出流对象fout中 
        while(fin.get(ch)) 
            fout << ch;
        
        fin.close();  // 关闭文件输入流对象fin与文件filename1的关联 
        
        fout << endl; // 向文件输出流对象fout中插入换行 
        
        
        fin.open(filename2);  // 将输入文件流对象fin与文件filename2建立关联 
        if(!fin.is_open()) {  // 如果打开文件失败，则输出错误提示信息并退出
            cerr << "fail to open file " << filename2 << endl;
            exit(0);    
        }
        
        // 从文件输入流对象fin中获取字符，并将其插入到文件输出流对象fout中
        while(fin.get(ch))
            fout << ch;
        
        fin.close();     // 关闭文件输入流对象fin与文件filename2的关联
        fout.close();    // 关闭文件输出流对象fout与文件newfilename的关联
        
        ofstream fapp;
        fapp.open(newfilename,ios_base::app);
        fapp<<endl;
        fapp<<"merge successfully.";
        fapp.close();
        system("pause");
    
        return 0;
    }

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#include <iostream>
    #include<fstream>
    #include <string>
    #include <cstdlib>
    #include<sstream>
    #include<ctime>
    #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 "<<filename << endl;
    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 <string>
    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 <ctime>
    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));

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转载于:https://www.cnblogs.com/hongzai1206/p/11043985.html

[ContractedBlock.gif]: https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif
[ExpandedBlockStart.gif]: /images/20211220/cb07ea3a932a451f8bd3e49aa4fe61c4.png
[1615571-20190618104600135-695137454.png]: /images/20211220/63729d3503804ef4ad80acc5f7cba24f.png
[1615571-20190618104654139-432084978.png]: /images/20211220/186d12d9e0384b37b02a7652ea018f08.png