map 基本用法 (输入字符串与数值，统计输入字符串次数及该数据的平均值)

#include<iostream>#include<map>#include<string>#include<algorithm>

using namespace std;

struct Data{   Data(): cout(0),sum(0) {}   int cout;   double sum;};

typedef map<string,Data> M;

void CollData(M &m){   string name;   double value;

   for (;;)   {      cin>>name;      if (name == "exit")       break;      cin>>value;             m[name].sum += value;       ++m[name].cout;    }}

 

int main(){

   M m;   CollData(m);

   map<string,Data>::const_iterator iter = m.begin();   while(iter != m.end())   {       cout<<iter->first<<" 输入次数 "<<iter->second.cout<<" 平均值为 "<<(iter->second.sum)/(iter->second.cout)<<"/n";    ++iter;   }

   return 0;}