实验 7 流类库 与输入输出

11-7

#include<iostream>
using namespace std;
int main()
{
    ios_base::fmtflags original_flags=cout.flags();//保存现在的格式化参数
    cout<<812<<'|';
    cout.setf(ios_base::left,ios_base::adjustfield);//取消其他对齐，设置为左对齐 
    cout.width(10);//为各项指定输出宽度10字符 
    cout<<813<<815<<'\n';
    cout.unsetf(ios_base::adjustfield);//取消格式
    cout.precision(2);//设定输出值以新的浮点数精度值显示，即小数点后保留2位 
    cout.setf(ios_base::uppercase|ios_base::scientific);//以科学格式显示浮点数值，对于科学格式显示大写字母E 
    cout<<831.0;
    cout.flags(original_flags);//恢复初始的的格式化参数
    return 0;
}

11-3

#include<iostream>
#include<fstream>
#include<Windows.h> 
using namespace std;
int main()
{    
    ofstream outFile;
    outFile.open(("D:\\text1.txt"));
       outFile<<"已成功写入文件"<<endl;
       outFile.close();
       WinExec("notepad.exe D:\\text1.txt",SW_SHOW);
       system("pause");
    return 0;
}

11-4

#include<iostream>
#include<fstream>
#include<string> 
using namespace std;
int main()
{
    
        ifstream outFile("D:\\text1.txt");
        string file;
        if(outFile)
        {
            while(getline(outFile,file))
            {
                cout<<file<<endl;
            }
        }
        outFile.close();
    return 0;
}

1

#include<iostream>
#include<fstream>
#include<string>
#include<cstdlib>
#include<ctime>
using namespace std;
struct student
    {
        string num1;
        string num2;
        string name;
        string c;
        
    };
int main()
{
    
    student stu[100];
    int i=0;
    ifstream inFile("list.txt");
    if(!inFile)
    {
        cout<<"无法打开文件"<<endl;
        return 1; 
    }
    while(inFile>>stu[i].num1>>stu[i].num2>>stu[i].name>>stu[i].c)
    {
        i++;
    }
    inFile.close();
    ofstream outFile("roll.txt");
    for(int j=0;j<5;j++)
    {
        srand((unsigned)time(NULL));
        int x;
        x=rand()%84;
        cout<<stu[j].num1<<" "<<stu[j].num2<<" "<<stu[j].name<<" "<<stu[j].c<<endl;
        outFile<<stu[j].num1<<" "<<stu[j].num2<<" "<<stu[j].name<<" "<<stu[j].c<<endl;
    }
    outFile.close();
    
    return 0;
}

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2

#include<iostream>
#include<fstream>
#include<cstring>
#include<vector>
#include<ctime>
#include<cstdlib>
using namespace std;
int main()
{
    ifstream outFile("text2.txt");
    int zf=0,word=0,line=0;
    char a[1000];
    while(outFile.getline(a,1000))
    {
        for(int i=0;i<strlen(a);i++)
        {
            zf++;
            if(a[i]>='A'&&a[i]<='Z'||a[i]>='a'&&a[i]<='z')
            {
                if(a[i-1]>='A'&&a[i-1]<='Z'||a[i-1]>='a'&&a[i-1]<='z')
                {
                    if(a[i+1]=='.'||a[i+1]==','||a[i+1]==' '||a[i+1]=='?'||a[i+1]=='!')
                    word++;
                }
                if(a[i-1]>=' ')
                {
                    if(a[i+1]=='.'||a[i+1]==','||a[i+1]=='?'||a[i+1]=='!')
                    word++;
                }
            }
            
            
        }
        line++;
    }
    cout<<"字符："<<zf<<endl<<"单词："<<word<<endl<<"行："<<line; 
    outFile.close();
    return 0;
}