words_replace.cpp

A group of word-analysis examples for C++/STL novices

/*
*  Description:
*
*    Find & Replace a word in a sentence.
*
*  History:
*
*    Initial version created by Royal, Mar. 2004.
*
*  Notes:
*
*    This code has been written to conform to standard C++ and STL. It has been
*    compiled successfully using GNU C++ 3.2, Borland C++ 5.5, and Visual C++ 7.0.
*/

#include <iostream>
#include <iomanip>
#include <vector>
#include <string>

using namespace std;

bool search(const vector<string>& sentence, vector<int>& pos, const string& word);
void replace(vector<string>& sentence, const vector<int>& pos, const string& word);
bool report_pos(const vector<string>& sentence, vector<int>& pos, const string& word);
void print(const vector<string>& sentence);

int main()
{
    vector<string> sentence;
    vector<int> pos;

    string input;
    cout<<"Please input a sentence:" << endl;
    while(cin >> input) sentence.push_back(input);
    cin.clear();

    string word1;
    cout<<"Please input the word you want to find:" << endl;
    cin >> word1;
    if (!report_pos(sentence, pos, word1)) return 1;

    cout << "Please input the word you want to change to be:" << endl;
    string word2;
    cin >> word2;
    cout << "The sentence before changed is:" << endl;
    print(sentence);	
    replace(sentence, pos, word2);
    cout << "The sentence after changed is:" << endl;
    print(sentence);
    return 0;
}
	
bool search(const vector<string>& sentence, vector<int>& pos, const string& word)
{
    vector<string>::size_type size = sentence.size();
    for(vector<string>::size_type i = 0; i < size; ++i)
        if(sentence[i] == word) pos.push_back(i);
    return !pos.empty();
}

void replace(vector<string>& sentence, const vector<int>& pos, const string& word)
{
    vector<int>::size_type size = pos.size();
    for(vector<int>::size_type i = 0; i < size; ++i) sentence[pos[i]] = word;
}

void print(const vector<string>& sentence)
{
    vector<string>::size_type size = sentence.size();
    for(vector<string>::size_type i = 0; i < size; ++i) cout << sentence[i] << " ";
    cout << endl;
}

bool report_pos(const vector<string>& sentence, vector<int>& pos, const string& word)
{
    if(search(sentence, pos, word))
    {
        cout << "Find the word at the following position: ";
        vector<int>::size_type size = pos.size();
        for(vector<int>::size_type i = 0; i < size; ++i) cout << setw(3) << pos[i] + 1;
        cout << endl;
        return true;
    }
    else
    {
        cout << "Can't find the word." << endl;
        return false;
    }
}