第十章：单词出现次数程序

//通过建立map对象保存所读入的单词及其出现次数；

//统计并输出所读入的单词出现的次数；

//使用insert函数代替下标操作

#include <iostream>

#include <map>

#include <utility>

#include <string>

using namespace std;

int main()

{

map<string,int> wordCount;

string word;

//读入单词并统计其出现的次数

cout<<"enter some words(Ctrl+Z to end):"<<endl;

while(cin>>word)

{

//插入元素<word,1>

pair<map<string,int>::iterator,bool> ret=wordCount.insert(make_pair(word,1));

if(!ret.second)//该单词已在容器中存在

++ret.first->second;//将该单词出现的次数加1

}

//输出结果

cout<<"word\t\t"<<"times"<<endl;

for(map<string,int>::iterator iter=wordCount.begin();iter!=wordCount.end();++iter)

cout<<(*iter).first<<"\t\t"<<(*iter).second<<endl;

//用map对象的迭代遍历输出单词以及它出现的次数

map<string,int>::const_iterator map_it=wordCount.begin();

while(map_it!=wordCount.end())

{

cout<<map_it->first<<" occurs "<<map_it->second<<" times "<<endl;

++map_it;

}

return 0;

}

//通过建立map对象保存所读入的单词及其出现次数；

//统计并输出所读入的单词出现的次数；

#include <iostream>

#include <map>

#include <string>

using namespace std;

int main()

{

map<string,int> wordCount;

string word;

cout<<"enter some words(Ctrl+Z to end):"<<endl;

while(cin>>word)

++wordCount[word];

cout<<"word\t\t"<<"times"<<endl;

for(map<string,int>::iterator iter=wordCount.begin();iter!=wordCount.end();++iter)

cout<<(*iter).first<<"\t\t"<<(*iter).second<<endl;

return 0;

}