C++primer plus第六版课后编程题答案17.4

main174.cpp

#include <iostream>#include <fstream>#include <string>using namespace std;void main174(){ifstream fin1("input1.txt");ifstream fin2("input2.txt");ofstream fout("output.txt");if(!fin1.is_open())cout<<" input1.txt open failure!"<<endl;if(!fin2.is_open())cout<<" input2.txt open failure!"<<endl;if(!fout.is_open())cout<<" output.txt open failure!"<<endl;string temp;while(fin1.good()&&fin2.good()){getline(fin1,temp);fout<<temp;fout<<" ";getline(fin2,temp);fout<<temp;fout<<endl;}if(fin1.eof()&&!fin2.eof())//1完了，2没完{while(fin2.good()){getline(fin2,temp);fout<<temp;fout<<endl;}}if(fin2.eof()&&!fin1.eof()){while(fin1.good()){getline(fin1,temp);fout<<temp;fout<<endl;}}if(fin1.eof()&&fin2.eof())cout<<"copy complete!"<<endl;elsecout<<"something bad!"<<endl;fin1.close();fin2.close();fout.close();}