实验7

我的博客园出了点问题，上传了第一张图片之后就显示未登录，没法继续上传图片，所以只有11-7有图片了，望见谅。



#include<iostream>
using namespace std;
int main()
{
    ios_base::fmtflags original_flags=cout.flags();
    cout<<812<<'|';
    cout.setf(ios_base::left,ios_base::adjustfield);  /*将格式调整为左对齐*/
    cout.width(10);                                   /*设置宽度为10 */
    cout<<813<<815<<'\n';
    cout.unsetf(ios_base::adjustfield);              /*取消已设的格式定义 */
    cout.precision(2);                               /*设置精度为2 */
    cout.setf(ios_base::uppercase|ios_base::scientific);/*用科学格式显示浮点数值 ，对于科学数值显示大写字母E*/ 
    cout<<813.0;
    cout.flags(original_flags);                     /*回复初始 */
    return 0;
} 

 

2.11-3

#include<iostream>
#include<fstream>
using namespace std;
int main()
{   
    ofstream out("text.txt");
    out<<"已成功写入文件！";
    out.close(); 
     return 0;
 } 

 3.11-4

include <iostream>
#include <fstream>
#include <string>
using namespace std;
int main() {
    string s;
    ifstream in("test1.txt");
    if(!in) {
        cout << "fail to open." << endl;
        return 1;
    }
    in >>  s;
    cout << s;
    in.close();
    return 0;
}

4

#include<iostream>
#include<fstream>
#include<string>
#include<stdlib.h>
using namespace std;
int m;
struct student
{
    string num;
    string stuid,name,cls;
}stu[100];
int main(){
    ifstream in("list.txt");
    int i=0;
    while(in>>stu[i].num>>stu[i].stuid>>stu[i].name>>stu[i].cls)
    {
        i++;
    }
    in.close();
    ofstream out("roll.txt");
    for(int i=1;i<=5;++i)
    {
        srand((unsigned)time(NULL));
        int a=rand()%a.size();
        cout<<stu[a].num<<" "<<stu[a].stuid<<" "<<stu[a].name<<" "<<stu[a].cls<<endl;
        out<<stu[a].num<<" "<<stu[a].stuid<<" "<<stu[a].name<<" "<<stu[a].cls<<endl;
    }
    out.close();
    return 0;
｝

 

5

#include<bits/stdc++.h>
using namespace std;
const char de[]={'"',',',' ','.','\0','!','?','-','(',')','#','/',':'};//分割字符串，配合strtok使用
int main(){
cout<<"Please Enter filename:\n";
string filename;
cin>>filename;
ifstream fin(filename.c_str());
string line;
long long linenum=0,chnum=0,wordnum=0;
while(getline(fin,line)){
    char *tmp=new char[line.length()+1];
    strcpy(tmp,line.c_str());
    char *tmp2;
    tmp2=strtok(tmp,de);  /*这里是用的分割字符串，可以将符号都变成\0*/
    if(tmp2!="")wordnum++;
    while((tmp2=strtok(NULL,de)))wordnum++;
    linenum++;
    chnum+=line.size();
}
cout<<"行数："<<linenum<<" 字符数："<<chnum<<" 单词数："<<wordnum;
fin.close();
return 0;
}