string_hash.h

聚类分析程序 k-means 编译环境 gcc/stl

#include <ext/hash_map>
#include <string>
#include <iostream>
using namespace std;
using namespace __gnu_cxx;

struct eqstr
{
  bool operator()(const string s1, const string s2) const
  {
    return strcmp(s1.c_str(), s2.c_str()) == 0;
  }
};

namespace __gnu_cxx {
  template <> struct hash<const string>
  {
    size_t operator()(const string& s) const
    {
      return hash<char const*>()(s.c_str());
    }
  };
};


typedef hash_map<const string,unsigned int,hash<const string>,eqstr> HASHM;
typedef HASHM::iterator HASHMI;  // const doesn't change behavior
class stringHash{

public:
  void dumpAllValues(){   
    cout << "dump 1:" << endl;  // list all content
    for (HASHMI i=h.begin();i!=h.end();i++) cout<<i->first<<" "<<i->second<<endl;
  }
  
  void erase(HASHM::iterator it){ h.erase(it); }
  void insert(string s, int n){ h.insert( make_pair(s, n) ) ;}
  unsigned int get(string s) { return h[s]; }
  void increment(string s) { h[s]++; }
  
  inline HASHMI begin() { return h.begin(); }
  inline HASHMI end() { return h.end(); }

  
 private:
  HASHM h; string n;
  
  
  /*   n="hello";      h[n]=20;  n="goodbye";    h[n]=10; */
  /*   n="yesterday";  h.insert( make_pair(n, 30) ); */
  /*   n="today";      h.insert( make_pair(n.c_str(), 40) ); */
  
  
  
  /*   // Let's erase some items: */
  /*   h.erase(h.begin());        // Erase whichever element is first */
  /*   h.erase("hello");          // Erase a specific element */
  
  /*   cout << "dump 2:" << endl; // list all content again */
  /*   for(HASHMI i=h.begin();i!=h.end();i++) cout<<i->first<<" "<<i->second<<endl; */
  
  /*   // h.clear();              // Works fine */
  
  /*   // Loop to delete specific elements works OK. */
  /*   HASHMI i=h.begin(); */
  /*   while (! h.empty()) { */
  /*     // h.erase((*i).first); // works */
  /*     h.erase(h.begin());     // works */
  /*     // h.erase(i);          // won't compile   */
  /*     i=h.begin(); */
  /*   } */
  
  /*   // Loop to delete all elements one at a time will NOT work,  */
  /*   // regardless of iterator type.  Elements will delete OK, but */
  /*   // the loop either doesn't finish or segfaults */
  /*   for(HASHMI i=h.begin();i!=h.end();++i) { */
  /*     // h.erase(i);         // won't compile */
  /*     // h.erase(h.begin()); // segfaults */
  /*     // h.erase((*i).first);// segfaults */
  /*   } cout << "size at end=" << h.size() << endl; return(0); */
  /*   } */
};