單源最短路徑BellmanFord演算法實現檔案C++

 

//graphRepresentAsAdjacentList.cpp -- mplement file#include "stdafx.h"#include "graphRepresentAsAdjacentList.h"//Purpose://Define methods of class "graphRepresentAsAdjacentList".//Private methods://---------------------graphRepresentAsAdjacentList ::Vertex * graphRepresentAsAdjacentList ::m_makeVertex (int indexInAdjacentList, int weight){Vertex * newVertex = new Vertex ;if (newVertex != NULL){newVertex ->indexInAdjacentList = indexInAdjacentList ;newVertex ->weight = weight ;newVertex ->next = NULL ;}return newVertex ;}//---------------------//---------------------//Assume the graph has been imported perfectly and//0 <= sourceVertex < m_size.void graphRepresentAsAdjacentList ::m_initializeSingleSource (int sourceVertex){for (vector<int> ::iterator iter = m_distanceVector.begin(); iter != m_distanceVector.end(); ++iter){*iter = Infinity ;}for (vector<int> ::iterator iter = m_parentVector.begin(); iter != m_parentVector.end(); ++iter){*iter = Nil ;}m_distanceVector[sourceVertex] = 0 ;}//---------------------//---------------------int graphRepresentAsAdjacentList ::m_distanceBetweenTwoVertexes (int startVertex, int endVertex){Vertex * scan = m_adjacentListVector[startVertex].next ;while (scan != NULL){if (endVertex == scan ->indexInAdjacentList)return scan ->weight ;scan = scan ->next ;}return Infinity ;}//---------------------//---------------------//Assume both startVertex and endVertex are in the correct range.void graphRepresentAsAdjacentList ::m_relax (int startVertex, int endVertex){if (m_distanceVector[endVertex] > m_distanceVector[startVertex] + m_distanceBetweenTwoVertexes(startVertex, endVertex)){m_distanceVector[endVertex] = m_distanceVector[startVertex] + m_distanceBetweenTwoVertexes(startVertex, endVertex) ;m_parentVector[endVertex] = startVertex ;}}//---------------------//Public methods://---------------------graphRepresentAsAdjacentList ::graphRepresentAsAdjacentList (int size){if (size <= 0){std ::cerr << "Wrong size." << std ::endl ;return ;}m_size = size ;m_currentSize = 0 ;//Set the size of following vertexes only.m_parentVector.resize(m_size) ;m_distanceVector.resize(m_size) ;}//---------------------//---------------------graphRepresentAsAdjacentList ::~graphRepresentAsAdjacentList (void){m_adjacentListVector.erase(m_adjacentListVector.begin(), m_adjacentListVector.end()) ;}//---------------------//---------------------bool graphRepresentAsAdjacentList ::importAVertex (const std ::vector<int> & indexVector, const std ::vector<int> & weightVector){static Vertex vertex ;if (m_currentSize < m_size){vertex.indexInAdjacentList = m_currentSize ;//W[u][u] is 0 and m_adjacentListVector[m_currentSize] is the vertex u.vertex.weight = 0 ;vertex.next = NULL ;m_adjacentListVector.push_back(vertex) ;if (indexVector.size() != 0){vector<int> ::size_type iIndex = 0 ;vector<int> ::size_type iWeight = 0 ;Vertex * newVertex = m_makeVertex(indexVector[iIndex++], weightVector[iWeight++]) ;if (newVertex != NULL){m_adjacentListVector[m_currentSize].next = newVertex ;while (iIndex != indexVector.size()){Vertex * anotherNewVertex = m_makeVertex(indexVector[iIndex++], weightVector[iWeight++]) ;if (anotherNewVertex != NULL){newVertex ->next = anotherNewVertex ;newVertex = anotherNewVertex ;}else{return false ;}}}else{return false ;}}++m_currentSize ;return true ;}std ::cerr << "All vertexes have been imported." << std ::endl ;return false ;}//---------------------bool graphRepresentAsAdjacentList ::bellmanFord (int sourceVertex){m_initializeSingleSource(sourceVertex) ;//The loop runs m_size - 1 times.for (int i = 0; i != m_size - 1; ++i){//For each edge in the graph.for (vector<Vertex> ::const_iterator iter = m_adjacentListVector.begin(); iter != m_adjacentListVector.end(); ++iter){Vertex * scan = iter ->next ;while (scan != NULL){//A edge has been found.m_relax(iter ->indexInAdjacentList, scan ->indexInAdjacentList) ;scan = scan ->next ;}}}//Test if there is a negative circle.for (vector<Vertex> ::const_iterator iter = m_adjacentListVector.begin(); iter != m_adjacentListVector.end(); ++iter){Vertex * scan = iter ->next ;while (scan != NULL){if (m_distanceVector[scan ->indexInAdjacentList] >m_distanceVector[iter ->indexInAdjacentList] + m_distanceBetweenTwoVertexes(iter ->indexInAdjacentList, scan ->indexInAdjacentList)){return false ;}scan = scan ->next ;}}return true ;}//---------------------//---------------------void graphRepresentAsAdjacentList ::printEachShortestPathValueFromSourceVertex (int startVertex){vector<Vertex> ::size_type i = 0 ;while (i != startVertex){std ::cout << "V[" << startVertex << "] ->" << "V[" << i << "]: " << m_distanceVector[i] << std ::endl ;++i ;}i = startVertex + 1 ;vector<Vertex> ::size_type size = m_size ;while (i != size){std ::cout << "V[" << startVertex << "] ->" << "V[" << i << "]: " << m_distanceVector[i] << std ::endl ;++i ;}}//---------------------//---------------------void graphRepresentAsAdjacentList ::printGraph (void){for (vector<Vertex> ::size_type i = 0; i != m_adjacentListVector.size(); ++i){std ::cout << "V[" << i << "] ->" ;Vertex * scan = m_adjacentListVector[i].next ;while (scan != NULL){std ::cout << "V[" << scan ->indexInAdjacentList << "] weight: " << scan ->weight << " ->" ;scan = scan ->next ;}std ::cout << std ::endl ;}}//---------------------//End of file.