并查集类的c++封装，比较union_find algorithm四种实现方法之间的性能差别

问题描述：

在计算机科学中，并查集是一种树型的数据结构，其保持着用于处理一些不相交集合（Disjoint Sets）的合并及查询问题。有一个联合-查找算法（union-find algorithm）定义了两个操作用于此数据结构：

Find：确定元素属于哪一个子集。它可以被用来确定两个元素是否属于同一子集；

Union：将两个子集合并成同一个集合；

实现并查集的关键是实现union-find algorithm, 本文根据常用的四种算法，实现了这个类，具体算法实现请参看维基百科；

制造测试数据集，测试几种方法之间性能的指标；

程序代码：

        

#ifndef _DISJOINT_SET_H_#define _DISJOINT_SET_H_#include <stdlib.h>#include <stdio.h>#include <assert.h>#include <time.h>#include <math.h>#include "windows.h"enum DISJOINTWAY{COMMON_WAY,COMPREE_WAY,WEIGHT_WAY,WEIGHT_COMPRESS_WAY};/** encapsulate the class of disjoint set **/#define MAXDISJOINTSET 0xffffffclass DisjointSet{public:DisjointSet( int maxSize = MAXDISJOINTSET ):m_item(0), m_size(maxSize){m_item = new int[maxSize];for( int i = 0; i < m_size; i++ ){m_item[i] = i;}m_path = new int[maxSize];memset( m_path, 1, sizeof(int)*maxSize );}~DisjointSet(){Clear();}/** find interface **/int Find( DISJOINTWAY way, int input ){assert( input <  m_size );switch( way ){case COMMON_WAY:return ImplFindFirst( input );case COMPREE_WAY:return ImplFindSecond( input );case WEIGHT_WAY:return ImplFindWeight( input );case WEIGHT_COMPRESS_WAY:return ImplFindWeightCompree( input );default:return -1;}}/** make union**/void Union( DISJOINTWAY way, int first, int second ){assert( first < m_size && second < m_size );switch( way ){case COMMON_WAY:ImplUnionFirst( first, second );break;case COMPREE_WAY:ImplUnionSecond( first, second );break;case WEIGHT_WAY:ImplUnionWeighted( first, second );break;case WEIGHT_COMPRESS_WAY:ImplUnionCompree( first, second );break;default:break;}}/****/void Clear(){delete [] m_item;m_item = 0;delete [] m_path;m_path = 0;m_size = 0;}protected:int ImplFindFirst( int input ){assert( input < m_size  );return m_item[input];}int ImplFindSecond( int input ){int i = input;for( ; i != m_item[i]; i = m_item[i] );return i;}int ImplFindWeight( int input ){int i = input;for( ; i != m_item[i]; i = m_item[i] );return i;}int ImplFindWeightCompree( int input ){int i = input;for( ; i != m_item[i]; i = m_item[i] )m_item[i] = m_item[m_item[i]];return i;}/****/void ImplUnionFirst( int first, int second ){int x = m_item[first];int y = m_item[second];if( x != y ){m_item[first] = y;}for( int i = 0; i < m_size; i++ ){if( x == m_item[i] )m_item[i] = y;}}/****/void ImplUnionSecond( int& first, int& second ){if( first != second ){m_item[first] = second;}}/****/void ImplUnionWeighted( int first, int second ){if( first != second ){if( m_path[first] < m_path[second] ){m_item[first] = second;m_path[second] += m_path[first];}else{m_item[second] = first;m_path[first] += m_path[second];}}}/****/void ImplUnionCompree( int first, int second ){if( first != second ){if( m_path[first] < m_path[second] ){m_item[first] = second;m_path[second] += m_path[first];}else{m_item[second] = first;m_path[first] += m_path[second];}}}protected:int*   m_item;int    m_size;int*   m_path;};void TestDisjointSetSimple(){DisjointSet djoint;int i = djoint.Find( COMMON_WAY, 1 );int j = djoint.Find( COMMON_WAY, 3 );if( i != j )djoint.Union( COMMON_WAY, 1, 3 );i = djoint.Find( COMMON_WAY, 2 );j = djoint.Find( COMMON_WAY, 5 );if( i != j )djoint.Union( COMMON_WAY, i, j );i = djoint.Find( COMMON_WAY, 2 );j = djoint.Find( COMMON_WAY, 6 );if( i != j )djoint.Union( COMMON_WAY, i, j );i = djoint.Find( COMMON_WAY, 6 );j = djoint.Find( COMMON_WAY, 7 );if( i != j )djoint.Union( COMMON_WAY, i, j );assert( djoint.Find( COMMON_WAY, 2 ) == djoint.Find( COMMON_WAY, 7 ) );i = djoint.Find( COMMON_WAY, 1 );j = djoint.Find( COMMON_WAY, 7 );if( i != j )djoint.Union( COMMON_WAY, i, j );assert( djoint.Find( COMMON_WAY, 3 ) == djoint.Find( COMMON_WAY, 7 ) );}void TestDisjointSetComplex( DISJOINTWAY way, const char* str ){    unsigned long start = GetTickCount();DisjointSet djoint;const int len = 1000000;const int base = 60000;int halfLen = len / 2;srand( time(NULL) );for( int i = 0; i < len; i++ ){int first = rand() % base;int second = rand() % base;if( i > halfLen ){first += base;second += base;}if( first != second ){first = djoint.Find( way, first );second = djoint.Find( way, second );if( first != second )djoint.Union( way, first, second );assert( djoint.Find( way, first ) == djoint.Find( way, second )  );}}unsigned long interval = GetTickCount() - start;printf(" %s way consume time is %d \n", str, interval );}void TestSuiteDisjointSet(){TestDisjointSetSimple();const char* str[] = {"common", "compress", "weight", "weight compress"};for( int i = WEIGHT_COMPRESS_WAY; i >= 0; i--){TestDisjointSetComplex((DISJOINTWAY)i, str[i] );}}#endif 

compile and run in visual studio 2005

下面图片是几种方法运行时间之比较，最直白方法的时间到现在还没输出，所以就没有显示：