uva 123 - Searching Quickly

这题是wa,现在没时间改，应该是单词搜寻那里有问题，搜th，the也能搜到

#include<iostream>
#include<string>
#include<vector>
#include<algorithm>
#include<sstream>
using namespace std;
typedef struct combine{
    string word;
    int i;
    string replaceword;
    bool operator <= (const combine& b) const{
        return word<=b.word;
    }
}combine;
bool cmp(combine a,combine b){
    if(a.word==b.word){
        return a.i<b.i;
    }
    else
        return a.word<b.word;
}
vector<combine> dictionnary;
int main(){
    vector<string> igwords;
    vector<string> sentence;
    string l;
    int len=0,temp=1;
    int i_sentence=0;
    int n;
    cin>>n;
    getchar();
    while(n--){
        getline(cin,l);
        if(l!="::"&&temp){
            igwords.push_back(l);
            continue;
        }
        else{
            if(temp){
                temp=0;
                continue;
            }
        }
        for(int i=0;i<l.size();i++)
            if(isupper(l[i]))
                l[i]=l[i]-'A'+'a';
        sentence.push_back(l);
        istringstream iss(l);
        vector<string>::iterator ig_it;
        for(string s_temp;iss>>s_temp;){
            ig_it=find(igwords.begin(),igwords.end(),s_temp);
            if(ig_it==igwords.end()){
                combine temp;
                temp.word=s_temp;
                temp.i=i_sentence;
                for(int j=0;j<s_temp.size();j++){
                    s_temp[j]-=32;
                }
                temp.replaceword=s_temp;
                dictionnary.push_back(temp);
            }
        }
        i_sentence++;
    }
    sort(dictionnary.begin(),dictionnary.end(),cmp);
    string pre_word="";
    int pre_sentence=0;
    int same_num=0;
    for(int i=0;i<dictionnary.size();i++){
        int start_pos=0;
        if((pre_sentence==dictionnary[i].i)&&pre_word==dictionnary[i].word){
            same_num++;
        }
        else
            same_num=0;
        string s_temp=sentence[dictionnary[i].i];//原title
        for(int j=0;j<same_num;j++){
            start_pos=s_temp.find(dictionnary[i].word,start_pos);
            if(!isalpha(start_pos-1))
            start_pos+=1;
        }
        start_pos=s_temp.find(dictionnary[i].word,start_pos);
        s_temp.replace(start_pos,dictionnary[i].word.size(),dictionnary[i].replaceword);
        cout<<s_temp<<endl;
        pre_word=dictionnary[i].word;
        pre_sentence=dictionnary[i].i;
    }
    system("pause");
}