wordlist.cpp

本程序给出了SSD5实验课中Recommended Exercise2的参考程序 内附有详细的注释 下载后请仔细参照源代码进行分析 切莫完全搬照

#include <iostream>
#include <fstream>
#include <string>
#include <cstdlib>

using namespace std;

const int INITIAL_LIST_CAPACITY = 10;

void build_wordlist (string* word_list, int capacity, string filename) {

    ifstream words;
    string word;
    int size = 0;

    
    word_list = new string[INITIAL_LIST_CAPACITY];
    capacity = INITIAL_LIST_CAPACITY;


    words.open (filename.c_str());

    if (!words) {
        cerr << "Could not open " << filename << endl;
        exit(EXIT_FAILURE);
    }

   
    words >> word;
    while (! words.eof()) {

        if (size > (capacity - 1)) {

            
            string new_word_list = *(new string[2 * capacity]);

       
            for (int index = 0; (index < capacity); index++) {
                new_word_list = word_list[index];
            }

            delete word_list;
            *word_list = new_word_list;

            capacity *= 2;
        }

       
        word_list[size] = word;
        size++;


        words >> word;
    }

    words.close();
}

int main (int argc, char *argv[]) {

    
    
    string *word_list = 0;
    int capacity = 0;

  
    build_wordlist (word_list, capacity, "words.txt");

  
    for (int index = 0; (index < capacity) && (word_list[index] != "");
            index++) {
        cout << word_list[index] << endl;
    }

    return EXIT_SUCCESS;
}