采用STL中的Vector容器实现词频统计与排序，代码如下：
#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
using namespace std;
int main()
{
string strInput = "我 爱 吃 苹果 ， 我 更 爱 吃 香蕉 。 ";
vector<string>vecWords;
unsigned int pos1 = 0;
unsigned int pos2 = 0;
pos2 = strInput.find(" ", pos1);
string strWord;
while(pos2 != string::npos)
{
strWord = strInput.substr(pos1, pos2 - pos1);
vecWords.push_back(strWord);
pos1 = pos2 + 1;
pos2 = strInput.find(" ", pos1);
}
sort(vecWords.begin(), vecWords.end());
unsigned int n = 0;
int nCount = 1;
for(n = 0; n < vecWords.size()-1; ++n)
{
if(vecWords[n] == vecWords[n+1])
{
nCount++;
}
else
{
cout << vecWords[n] << " " << nCount << endl;
nCount = 1;
}
}
if(vecWords[vecWords.size()-2] != vecWords[vecWords.size()-1])
cout << vecWords[vecWords.size()-1] << " " << 1 << endl;
}