实验7

Posted 2020-11-19 zzy4546

11-3

#include<iostream> 
#include<fstream>
using namespace std;
int main()
{   
    ofstream outfile("D:\\text1.txt");
    outfile<<"成功写入文件"<<endl;
    outfile.close();
    return 0;
}

11-4

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

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);//设置为左对齐 
    cout.width(10);//指定输出宽度10字符 
    cout<<813<<815<<‘
‘;
    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，小数点后保留2位 
    cout.setf(ios_base::uppercase|ios_base::scientific);//更改浮点数的显示方式，以科学显示浮点数值 
    cout<<831.0;
    cout.flags(original_flags);//恢复初始的的格式化参数
    return 0;
}

4

#include<iostream>
#include<fstream>
#include<string>
using namespace std;
int main() {
    ifstream infile("golden god.txt");
    int line = 0; int num1 = 0; int word = 0;
        string s1; int m;
        while (getline(infile, s1)) 
{
            m = s1.size();
            line++;
            num1 +=  m;
            for (int i = 0;i < m; i++) 
            {
                if (s1[i] >= ‘A‘&&s1[i] <= ‘Z‘ || s1[i] >= ‘a‘&&s1[i] <= ‘z‘)
                {
                    if (s1[i + 1] >= ‘!‘&&s1[i + 1] <= ‘/‘||s1[i+1]==‘ ‘||s1[i+1]>=‘:‘&&s1[i+1]<=‘?‘)
                    {
                        word++;
                    }
                }
            }
        }
    infile.close();
    cout <<"行数："<< line << " 字符数：" << num1 <<" 单词数："<<word<< endl;
    return 0;
}

#include<string.h>
#include<cstdlib>
#include<ctime>
using namespace std;
struct student
{
    string num1;
    string num2;
    string name;
    string classroom;
};
int main()
{
    student stu[100];
    ifstream infile("list.txt");
    int i=0;
    while(infile>>stu[i].num1>>stu[i].num2>>stu[i].name>>stu[i].classroom)
    {
        i++;
    }
    infile.close();
    ofstream outfile("roll.txt");
    srand((unsigned)time(NULL));//设立随机种子 
    for(int j=0;j<5;j++)//随机抽取
    {
        int r=rand() %84;
        cout<<stu[j].num1<<" "<<stu[i].num2<<" "<<stu[j].name<<" "<<stu[j].classroom<<endl;
        outfile<<stu[j].num1<<" "<<stu[i].num2<<" "<<stu[j].name<<" "<<stu[j].classroom<<endl;
    } 
    outfile.close();
    return 0;    
}

这一题 数据还是读不出来。。。我个人感觉代码还是没有问题，请大佬指点。。。