15第一部分

程序：

#include <iostream>
#include <fstream>
using namespace std;
int main()
{
    ifstream readFile;//建立两个对象
    ofstream writeFile;
    char ch;
    readFile.open("a.txt", ios::in);
    writeFile.open("b.txt", ios::out);
    while (readFile.get(ch))//读入单个字符
        writeFile.put(ch);
    readFile.close();//关闭文件
    writeFile.close();
    cout << "Finish!" << endl;
    return 0;
}

结果：

a

b