1、请写出下面程序的输出结果 （1）
#include <iostream> #include <fstream> using namespace std; int main() { fstream outfile,infile; outfile.open("data.dat",ios::out); outfile<<"1111111111"<<endl; outfile<<"aaaaaaaaaa"<<endl; outfile<<"AAAAAAAAAA"<<endl; outfile<<"**********"<<endl; outfile.close(); infile.open("data.dat",ios::in); char line[80]; int i=0; while(!infile.eof()) { i++; infile.getline(line,sizeof(line)); cout<<i<<": "<<line<<endl; } infile.close(); return 0; }（2）说出程序的功能，并上机验证（请自建a.txt）
#include <iostream> #include <fstream> using namespace std; int main() { ifstream readFile; ofstream writeFile; char ch; readFile.open("a.txt", ios::in); writeFile.open("b.txt", ios::out); while (readFile.get(ch)) writeFile.put(ch); readFile.close(); writeFile.close(); cout << "Finish!" << endl; return 0; }（3）
#include <iostream> #include <fstream> #include<cstring> using namespace std; int main() { ifstream readFile; ofstream writeFile; char ch[100]; readFile.open("a.txt", ios::in); writeFile.open("b.txt", ios::out); while (!readFile.eof()) { readFile.getline(ch,100,'\n'); writeFile.write(ch,strlen(ch)); writeFile.write("\n",1); } readFile.close(); writeFile.close(); cout << "Finish!" << endl; return 0; }2、阅读并运行下面的两个程序，分别用记事本和二进制文件阅读器（请自行下载Binary Viewer）。查看其内容，并理解二进制文件存储的原理。 （1）
#include <iostream> #include <fstream> #include <cstdlib> using namespace std; int main( ) { int a; ofstream outfile("f1.dat",ios::out); if(!outfile) { cerr<<"open error!"<<endl; exit(1); } cin>>a; outfile<<a<<endl; outfile.close(); return 0; }（2）
#include <iostream> #include <fstream> #include <cstdlib> using namespace std; int main( ) { int a; ofstream outfile("f2.dat",ios::out|ios::binary); if(!outfile) { cerr<<"open error!"<<endl; exit(1); } cin>>a; outfile.write((char*)&a, sizeof(int)); outfile.close(); return 0; }3、查看下面程序的输出，解释为什么会有这样的输出。
#include <iostream> #include <fstream> using namespace std; int main( ) { unsigned char a[] = {0xD4,0xB8,0xB7,0xAD,0xD7,0xAA,0xB5,0xC4,0x43,0x2B, 0x2B,0xBF,0xCE,0xCC,0xC3,0xCE,0xAA,0xC4,0xE3,0xB4, 0xF8,0xC0,0xB4,0xD1,0xA7,0xCF,0xB0,0xB7,0xBD,0xB7, 0xA8,0xB5,0xC4,0xB8,0xC4,0xB1,0xE4,0xA3,0xA1 }; ofstream outfile("f3.dat",ios::out|ios::binary); outfile.write((char*)a, sizeof(a)); outfile.close(); return 0; }4、阅读下面的程序，指出其功能，体会seekg()、tellg()等函数的功能及其用法 （1）
#include<iostream> #include <fstream> using namespace std; const char * filename = "a.txt"; int main () { long l,m; ifstream file (filename, ios::in|ios::binary); l = file.tellg(); file.seekg (0, ios::end); m = file.tellg(); file.close(); cout << "size of " << filename; cout << " is " << (m-l) << " bytes.\n"; return 0; }（2）
#include <fstream> using namespace std; int main () { long pos; ofstream outfile; outfile.open ("test.txt"); outfile.write ("This is an apple",16); pos=outfile.tellp(); outfile.seekp (pos-7); outfile.write (" sam",4); outfile.close(); return 0; }（3）
#include <iostream> #include <fstream> using namespace std; int main() { fstream outfile,infile; outfile.open("data.txt",ios::out); for (int i=0; i<26; i++) outfile<<(char)('A'+i); outfile.close(); infile.open("data.txt",ios::in); char ch; infile.seekg(6,ios::beg); if(infile.get(ch)) cout<<ch; infile.seekg(8,ios::beg); if(infile.get(ch)) cout<<ch; infile.seekg(-8,ios::end); if(infile.get(ch)) cout<<ch; cout<<endl; infile.close(); return 0; }