c++ primer 10.3.9

#include <iostream>
#include <fstream>
#include <string>
#include <sstream>
#include <map>
using namespace::std;

int main()
{
    string f1("D://1.txt"),f2("D://2.txt"),f3("D://3.txt");
    map<string,string> map_trans;
    string key,value;
    ifstream trans_file(f1.c_str());
    if(!trans_file)
    cerr<<"No translation file!"<<endl;
    while(trans_file>>key>>value)
    map_trans.insert(make_pair(key,value));
    // Read the translation file and build map
    ifstream input_file(f2.c_str());
    if(!input_file)
    cerr<<"No input file!"<<endl;
    ofstream output_file(f3.c_str());
    if(!output_file)
    cerr<<"No Output file!"<<endl;
    string line;
    while(getline(input_file,line))
    {
     istringstream stream(line);
     string word;
     bool firstword=true;             
     while(stream>>word)
     {
     map<string,string>::const_iterator map_it=map_trans.find(word);
     if(map_it!=map_trans.end())
     word=map_it->second;
     if(firstword)
     firstword=false;
     else output_file<<" ";
     output_file<<word;
                        }
     output_file<<endl;               
    }
    system("pause");
    return 0;  
    }

 

1.txt 內容初始化

'em them cuz because grantz grateful i I nah no pos supposed sez said tanx thanks wuz was

 

2.txt 內容初始化

nah i sez tanx cuz i wuz pos to not cuz i wuz grantz

 

3.txt 裡面將輸出

no I said thanks because I was supposed to not because I was grateful