findword.cpp

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

void FindWord(string &TargetWord, string &Phrase)
{
    cout << "Find: " << TargetWord << " in: \""<< Phrase<<"\"" << endl;
    std::transform(Phrase.begin(), Phrase.end(), Phrase.begin(), [](unsigned char c){ return std::tolower(c); });
    std::transform(TargetWord.begin(), TargetWord.end(), TargetWord.begin(), [](unsigned char c){ return std::tolower(c); });
    //cout << "lower phrase: " << Phrase << endl;
    //cout << "lower TargetWord: " << TargetWord << endl;
    string Space = " ";
    int Count = 0;
    int FirstPosition  = -1;
    auto SpacePosition = 0;
    auto NextSpacePosition = Phrase.find(Space);
    while (SpacePosition < Phrase.length())
    {
        // test string begins with Space
        if (SpacePosition == NextSpacePosition)
        {
            cout << "continue" << endl;
            NextSpacePosition = Phrase.find(Space, ++SpacePosition);
        }
        string Word = Phrase.substr(SpacePosition, NextSpacePosition-SpacePosition);
        
        //cout<< Word<< endl;
        
        // 找到目标单词就计数
        if (TargetWord.compare(Word) == 0)
        {
            if(Count == 0 ){
                FirstPosition = SpacePosition;
            }
            Count ++;
        }
        
        //找下一个空格位置
        SpacePosition = NextSpacePosition + Space.length();
        NextSpacePosition = Phrase.find(Space, SpacePosition);
        
        // 如果不是以空格结尾，也要把最后一个单词取出来
        if(NextSpacePosition == std::string::npos ) 
        {
            NextSpacePosition = Phrase.length();
        }
    }
    
    // 输出结果
    if(Count)
    {
        std::cout << "Count: " << Count << std::endl;
		std::cout << "FirstPosition: "<<FirstPosition+1 << std::endl;
    }
	else
		std::cout << "FirstPosition: "<<FirstPosition << std::endl;
}

int main()
{

    //创建测试例子
    std::vector<string> PhraseList, TargetWordList;
    TargetWordList.push_back(string("tst"));
    PhraseList.push_back(string("Tst test TsT"));
    
    TargetWordList.push_back(string("Do"));
    PhraseList.push_back(string("Just do it"));
    
    TargetWordList.push_back(string("2"));
    PhraseList.push_back(string("1 5"));
    
    //getline(cin, Phrase);
    //getline(cin, TargetWord);
    for(int ii =0 ; ii <  PhraseList.size();ii++)
    {
        FindWord(TargetWordList[ii], PhraseList[ii]);
    }
    
    return 0;
}