统计输入的单词中有几个长度大于n的，n是自己指定的，用函数对象实现

#ifndef COUNT_WORD_H
#define COUNT_WORD_H

#include <string.h>
#include <iostream>
#include <iterator>
#include <vector>
#include <algorithm>

class GT_cls{
public:
GT_cls(size_t val = 0)
:bound_(val){}
bool operator()(const std::string &s){
return s.size() >= bound_;
}
private:
std::string::size_type bound_;
};

class Word_count{
public:
Word_count(size_t val)
:GT_(val), wc_(0){}
void readWord();
void process();
void display();
private:
static bool isShorter(const std::string &s1, const std::string &s2);
std::vector<std::string> words_;
GT_cls GT_;
size_t wc_;
};

inline void Word_count::readWord(){
std::istream_iterator<std::string> cin_it(std::cin);
std::istream_iterator<std::string> end_of_stream;
while(cin_it != end_of_stream){
words_.push_back(*cin_it++);
}
}

inline void Word_count::process(){
sort(words_.begin(), words_.end());
std::vector<std::string>::iterator end_unique = \
unique(words_.begin(), words_.end());
words_.erase(end_unique, words_.end());
stable_sort(words_.begin(), words_.end(), isShorter);
wc_ = count_if(words_.begin(), words_.end(), GT_);
}

inline void Word_count::display(){
std::cout << "There are " << wc_ << " words." << std::endl;
for(std::vector<std::string>::iterator it = words_.begin(); it != words_.end(); ++it){
std::cout << *it << " ";
}
std::cout << std::endl;
}

inline bool Word_count::isShorter(const std::string &s1, const std::string &s2){
return s1.size() < s2.size();
}

#endif  /*COUNT_WORD_H*/