我们实现一个简单的文本查询程序。我们的程序允许用户在一个给定文件中查询单词，查询结果是单词在文件中出现的次数及所在行的列表。如果一个单词在一行中出现多次，此行只列出一次。
#include<iostream> #include<map> #include<set> #include<string> #include<vector> #include<fstream> #include<sstream> #include<algorithm> using namespace std; //主要完成将输入文件转换为map形式 map<int,vector<string>> runQueries(ifstream &infile) { map<int,vector<string>> map_word; int lines=0; string text; while(getline(infile,text)) { istringstream in(text); string word; while(in>>word) { map_word[lines].push_back(word); } ++lines; } return map_word; } int main() { ifstream in("1.txt"); map<int,vector<string>> map_word=runQueries(in); set<int> iset; string str; cin>>str; vector<string>::size_type lines=0; while(lines!=map_word.size()) { vector<string> tmp=map_word[lines]; auto iter=find(tmp.begin(),tmp.end(),str); if(iter!=tmp.end()) iset.insert(lines); lines++; } cout<<"elements occurs "<<iset.size()<<" times "<<endl; auto ss=iset.begin(); while(ss!=iset.end()) { cout<<"(line "<<*ss<<" )"<<" "; for(auto v:map_word[*ss]) cout<<v<<" "; cout<<endl; ++ss; } return 0; }
1.txt
Alice Emma has long flowing red hair. Her Daddy says when the wind blows through her hair, it looks almost alive, like a fiery bird in flight. A beautiful fiery bird, he tells her, magical but untamed. "Daddy, shush, there is no such thing," she tells him, at the same time wanting him to tell her more. Shyly, she asks, "I mean, Daddy, is there?" Alice Emma has long flowing red hair. Her Daddy says when the wind blows through her hair, it looks almost alive, like a fiery bird in flight. A beautiful fiery bird, he tells her, magical but untamed. "Daddy, shush, there is no such thing," she tells him, at the same time wanting him to tell her more. Shyly, she asks, "I mean, Daddy, is there?" Alice Emma has long flowing red hair. Her Daddy says when the wind blows through her hair, it looks almost alive, like a fiery bird in flight. A beautiful fiery bird, he tells her, magical but untamed. "Daddy, shush, there is no such thing," she tells him, at the same time wanting him to tell her more. Shyly, she asks, "I mean, Daddy, is there?"
运行结果如下：
