hashprobe.cpp

ALGAE是一个快速创建算法演示的框架。目前支持的算法实现语言包括java和c

#include <time.h>
#include <iostream>
#include <cstdlib>
#include <sstream>
#include <string>


using namespace std;

string itos (int i)
{
  ostringstream str;
  str << i;
  return str.str();
}


#include "hashset.h"

using namespace std;




void promptForInput(const char* prompt, int& input)
{
  string reply;
  bool OK = false;
  while (!OK)
    {
      cout << prompt << flush;
      cin >> reply;
      
      const char* replystr = reply.c_str();
      
      istringstream in (replystr);
      OK = !!(in >> input);
    }
}


struct StringHash 
{
  int operator() (const string& s) const {return s.length();}
};


typedef hash_set<string, 8, StringHash> HashTable;

HashTable* set;

bool firstTime = true;


void init()
{
  if (firstTime)
    {
      firstTime = false;
      set = new HashTable;
    }
}




void hashInsert()
{
  init();
  string v;
  cout << "String to insert? " << flush;
  cin >> v;
  bool inserted = set->insert (v);
  if (!inserted)
    cout << "Unable to insert " << v << " into table." << endl;
}

void hashSearch()
{
  init();
  string v;
  cout << "String to search for? " << flush;
  cin >> v;
  int k = set->count (v);
  cout << "count() returned " << k << endl;
}


void hashErase()
{
  init();
  string v;
  cout << "String to remove? " << flush;
  cin >> v;
  set->erase (v);
}

void hashClear()
{
  init();
  set->clear ();
}







int main (int nargs, char** args)
{
  time_t dummy;
  srand (time(&dummy));

  cout << "Hashing - linear probing\n" << endl;
  
  int reply;
  while (1)
    {
      cout << "1. Insert\n2. Erase\n3. Search\n4. Clear\n0. Quit"
	   << endl;
      promptForInput("Your choice? ", reply);
      if (reply < 1 || reply > 4)
	break;

      switch (reply) {

      case 1:
	hashInsert();
	break;

      case 2:
	hashErase();
	break;

      case 3:
	hashSearch();
	break;
	
      case 4:
	hashClear();
	break;
      }
    }

  return 0;

}