实验6

偏执的太偏执、 2021-11-09 07:42 271阅读 0赞

part 2

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// 合并两个文件内容到一个新文件中。
    // 文件名均从键盘输入
    
    #include <iostream>
    #include <fstream>   
    #include <string>
    #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;
            system("pause");
            exit(0);    
        }
        
        fout.open(newfilename);    // 将输出文件流对象fout与文件newfilename建立关联 
        if(!fout.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;
            system("pause");
            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;
            system("pause");
            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::app);
        if(!fapp.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 3.txt "<< endl;
            system("pause");
            exit(0);    
            }
        fapp<<endl<<"merge successfully.";
        fapp.close();
        
        system("pause");
        
        return 0;
    }

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**part 3**

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#include<iostream>
    #include<fstream>
    #include<string>
    #include<vector>
    #include<cstdlib>
    #include "utils.cpp"
    using namespace std;
    int main()
    {
        string filename;
        filename = getCurrentDate();
        string fn,temp;
        int cnt,recordcnt;
        ifstream fin;
        ofstream fout;
        vector<string> records;
        
        
        cout<<"输入名单列表文件名：";
        cin>>fn;
        
        
        fin.open(fn);
        if(!fin.is_open())
        {
            cerr << "fail to open file"<<fn<< endl;
            system("pause");
            exit(0);    
        
        } 
        
        
        while(getline(fin,temp))//读取
            records.push_back(temp);
        fin.close();
        recordcnt=records.size();
        
        cout<<"输入随机抽点人数："; 
        cin>>cnt;
        
        if(cnt>recordcnt) 
        {
            cerr<<"input number is too big"<<endl;
            system("pause");
            exit(0);
        }
        
        fout.open(filename);
        cout<<"随机抽点中..."<<endl;
        
        int hit;
        srand((int)time(NULL));
        
        for(int i=0;i<cnt;i++)
        {
            hit=rand()%(recordcnt);
            cout<<records[hit]<<endl;
            fout<<records[hit]<<endl;
            recordcnt--;
            records.erase(records.begin()+hit);
        }
        fout.close();
        system("pause");
        return 0;
    }

utils.cpp

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**part 4**

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#include<iostream>
    #include<fstream>
    #include<string>
    using namespace std;
    int main()
    {
        string fn,temp;
        char tch;
        ifstream fin;
        int charcnt,wordcnt,linecnt;
        
        cout<<"输入要统计的英文文本文件名：";
        cin>>fn;
        
        fin.open(fn);
        if(!fin.is_open())
        {
            cerr << "fail to open file"<<fn<< endl;
            system("pause");
            exit(0);    
        
        }  
        
        //统计字符
        charcnt = 0;
         while(fin.get(tch))
         charcnt++;
         charcnt--;
         
         //统计单词
         wordcnt=0;
         fin.close();
         fin.open(fn); 
         while(fin>>temp)
         wordcnt++;
         
         //统计行 
         linecnt=0;
         fin.close();
         fin.open(fn) ;
         while(getline(fin,temp))
         linecnt++;
         
         fin.close();
         
        cout<<"字符数："<<charcnt<<endl;
        cout<<"单词数："<<wordcnt<<endl;
        cout<<"行数："<<linecnt<<endl;
        
        system("pause");
        return 0; 
         
    }

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总结：不说了做了半天。

转载于:https://www.cnblogs.com/zcq1224/p/11044267.html

[ContractedBlock.gif]: https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif
[ExpandedBlockStart.gif]: /images/20211109/fae929b791444393845b0cc09c94f90a.png
[1614365-20190618100855685-1931985657.png]: /images/20211109/8f51af6241174a219cf1197ddd4cf41f.png
[1614365-20190618112453539-1906595589.png]: /images/20211109/10ea38c22326482a83b20bf162f6f909.png
[1614365-20190618112656411-328684050.png]: /images/20211109/bab872f0f697411f8b64277d23700452.png