因为你获取数目后，文件已经读完了

#include <iostream>
#include <fstream>
#include <string>
#include <vector>
using namespace std;

int main()
{
    const char* filename = "dictionary";
    ifstream infile( filename );
    if( !infile )
    {
        cerr << "Can't open this dictionary.\n";
        return 1;
    }

    // 输入
    size_t num = 0;
    vector<string> words;
    for( string word; infile>>word; )
    {
        ++num; // 其实根本不需要，因为数量可以从 words.size() 获得
        words.push_back( word );
    }

    // 输出
    for( size_t i=0; i!=words.size(); ++i )
        cout << words[i] << '\n';
    cout << "There are " << num << " words in this dictionary." << endl;

    return 0;
}

或者
#include <iostream>
#include <fstream>
#include <string>
#include <vector>
#include <iterator>
#include <algorithm>
using namespace std;

int main()
{
    const char* filename = "dictionary";
    ifstream infile( filename );
    if( !infile )
    {
        cerr << "Can't open this dictionary.\n";
        return 1;
    }

    // 输入
    vector<string> words = vector<string>( istream_iterator<string>(infile), istream_iterator<string>() );

    // 输出
    copy( words.begin(), words.end(), ostream_iterator<string>(cout,"\n") );
    cout << "There are " << words.size() << " words in this dictionary." << endl;

    return 0;
}

很好，很强大

你是用什么来写游戏的？visual c++ 那个？怎么我写的都是黑白程序的。。。求解。。