delete Data Structure

Author: tthhee

TextQuery/TextQuery.cpp

@@ -0,0 +1,72 @@
+#include "TextQuery.h"
+
+
+TextQuery::TextQuery(ifstream& infile):file(new vector<string>)
+{
+	string text;
+	while(getline(infile, text)) //对文件中的每一行
+	{
+		file->push_back(text); //保存一行文本
+		int n = file->size()-1; //记录行号
+		istringstream line(text); //分配一个字符串流
+		string word;
+		while(line >> word)   //提取一行字符串中的没一个单词
+		{
+			auto &lines = wm[word];  //lines 的类型为mapped_type是一个shared_ptr，指向set<line_no>
+			if(!lines)                //如果word在wm中不存在，则lines是一个空指针
+			{
+				lines.reset(new set<line_no>);        //如果不存在，为lines分配一个set空间,并用reset使lines指向新分配的set
+			}
+			lines->insert(n);        //将行号插入到对应word的set中
+		}
+	}
+}
+QueryResult TextQuery::query(const string& word) const
+{
+	static shared_ptr<set<line_no>> nodata(new set<line_no>); //如果未找到word，就返回这个指针
+	auto loc = wm.find(word);
+	if(loc == wm.end())
+	{
+		return QueryResult(word, file, nodata); //未找到
+	}
+	else
+	{
+		return QueryResult(word, file, loc->second);
+	}
+
+	
+}
+
+ostream& print(ostream &os, const QueryResult& qr)
+{
+	os << qr.sought << " occurs " << qr.lines->size()
+	   << "times:" << endl;
+	for(auto it : *qr.lines)
+	{
+		cout << "\t (line " << it+1 << ") ";
+		cout << *(qr.file->begin() + it) <<endl;
+	}
+	return os;
+}
+void runQueries(ifstream& infile)
+{
+	//infile 是一个ifstream，指向我们要处理的文件
+	TextQuery tq(infile);  //保存文件并建立map
+	//与用户交互：提示用户要输入的单词，完成查询并打印结果
+	while(true)
+	{
+		cout << "enter word to look for or 'q' to quit: ";
+		string s;
+		if(!(cin >> s) || s == "q")
+			break;
+		else
+			print(cout, tq.query(s)) << endl;
+	}
+}
+int main()
+{
+
+	ifstream infile("TextQuery.txt");
+	runQueries(infile);
+	return 0;
+}

TextQuery/TextQuery.exe

@@ -0,0 +1,35 @@
+#include <iostream>
+#include <vector>
+#include <string>
+#include <map>
+#include <set>
+#include <fstream>
+#include <memory>
+#include <sstream>
+using namespace std;
+using line_no = vector<string>::size_type;
+class QueryResult;
+class TextQuery
+{
+public:
+	
+	TextQuery(ifstream &infile);
+	QueryResult query(const string &word) const;
+private:
+	//定义输入文件的智能指针
+	shared_ptr<vector<string>> file;
+	//每个单词到它所在行号的集合的映射
+	map<string, shared_ptr<set<line_no>>> wm;
+}; 
+class QueryResult
+{
+private:
+	string sought;  //查询的单词
+	shared_ptr<vector<string>> file;  //指向查询文件的指针
+	shared_ptr<set<line_no>> lines;   //指向行号的指针
+public:
+	QueryResult(string s, shared_ptr<vector<string>> p, shared_ptr<set<line_no>> l):sought(s), file(p), lines(l){}
+	friend ostream& print(ostream&, const QueryResult&);
+
+
+};

TextQuery/TextQuery.h

@@ -0,0 +1,14 @@
+When love beckons to you follow him
+though his ways are 
+hard and steep And when 
+his wings enfold you 
+yield to him though the sword 
+hidden among his 
+pinions may wound you
+And when he speaks to you 
+believe in him 
+though his voice
+may shatter your dreams as 
+the north wind lays
+waste the garden.
+

TextQuery/TextQuery.txt

@@ -1,4 +1,4 @@
-#include<stdio.h>
+#include <stdio.h>
 void main()
 {
     printf("Hello World!");