最短路径(Dijkstra实现)

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>

#define MaxVertexNodeNumSize 1000
#define MaxVertexNodeNameSize 100

struct VertexBodyNode
{
    char VertexName[MaxVertexNodeNameSize];
    int ArcWeight;
    int VertexIndex;
    struct VertexBodyNode *Next;
};

struct VertexHeadNode
{
    char VertexName[MaxVertexNodeNameSize];
    int VertexWeight;
    struct VertexBodyNode *Next;
};

struct _Graph
{
    struct VertexHeadNode VertexHeadNodeList[MaxVertexNodeNumSize];
    int ArcNum,VertexNum;
};

int VertexName2Index(struct _Graph *DirectedGraph,char *VName)
{
    int i;
    for(i = 0; i < DirectedGraph -> VertexNum; i ++)
    {
        if(strcmp(DirectedGraph -> VertexHeadNodeList[i].VertexName,VName)==0)
        {
            return i;
        }
    }
    return -1;
}

void AddOneArc(struct _Graph *DirectedGraph,int ArcIndex_1,int ArcIndex_2,int AWeight)
{
    struct VertexBodyNode *BNode = malloc(sizeof(struct VertexBodyNode));

    strcpy(BNode -> VertexName,DirectedGraph -> VertexHeadNodeList[ArcIndex_2].VertexName);

    BNode -> ArcWeight = AWeight;
    BNode -> VertexIndex = ArcIndex_2;
    BNode -> Next = NULL;

    struct VertexBodyNode *TmpPointer;
    TmpPointer = DirectedGraph -> VertexHeadNodeList[ArcIndex_1].Next;
    while(TmpPointer != NULL && TmpPointer -> Next != NULL)
    {
        TmpPointer = TmpPointer -> Next;
    }
    if(TmpPointer==NULL)
    {
        DirectedGraph -> VertexHeadNodeList[ArcIndex_1].Next = BNode;
    }
    else
    {
        TmpPointer -> Next = BNode;
    }
}

struct _Graph *UGCreat(int ArcSum,int VertexSum)
{
    int i,j;
    struct _Graph *DirectedGraph = malloc(sizeof(struct _Graph));
    DirectedGraph -> ArcNum = ArcSum;
    DirectedGraph -> VertexNum = VertexSum;

    for(i = 0; i < VertexSum; i ++)
    {
        scanf("%s %d",DirectedGraph -> VertexHeadNodeList[i].VertexName,&DirectedGraph -> VertexHeadNodeList[i].VertexWeight);
    }

    for(i = 0; i < VertexSum; i ++)
    {
        DirectedGraph -> VertexHeadNodeList[i].Next = NULL;
    }

    for(i = 0; i < ArcSum; i ++)
    {
        char Arc_1[MaxVertexNodeNameSize];
        char Arc_2[MaxVertexNodeNameSize];
        int ArcIndex_1;
        int ArcIndex_2;
        int ArcWeight;

        scanf("%s %s %d",Arc_1,Arc_2,&ArcWeight);

        ArcIndex_1 = VertexName2Index(DirectedGraph,Arc_1);
        ArcIndex_2 = VertexName2Index(DirectedGraph,Arc_2);

        AddOneArc(DirectedGraph,ArcIndex_1,ArcIndex_2,ArcWeight);
    }
    return DirectedGraph;
}

void Travel(struct _Graph *DirectedGraph)
{
    char StartingPoint[MaxVertexNodeNameSize];
    char OverPoint[MaxVertexNodeNameSize];

    printf("Input start and over\n");
    scanf("%s %s",StartingPoint,OverPoint);

    int StartIndex = VertexName2Index(DirectedGraph,StartingPoint);
    int OverIndex = VertexName2Index(DirectedGraph,OverPoint);

    struct VertexBodyNode *TmpPointer;
    TmpPointer = DirectedGraph -> VertexHeadNodeList[StartIndex].Next;
    while(TmpPointer != NULL)
    {
        if(OverIndex==TmpPointer -> VertexIndex)
        {
            printf("Distance:%d GetVertexPointSum:%d",TmpPointer->ArcWeight
                   ,DirectedGraph -> VertexHeadNodeList[StartIndex].VertexWeight+DirectedGraph -> VertexHeadNodeList[OverIndex].VertexWeight);
            break;
        }
        else
        {
            TmpPointer = TmpPointer -> Next;
        }
    }
}

void DijkstraShortestPath(struct _Graph *DirectedGraph,char *Origin,char *Destination)
{
    int Visit[DirectedGraph->VertexNum];
    int Distance[DirectedGraph->VertexNum];
    int PathResult[DirectedGraph->VertexNum];
    int OIndex = VertexName2Index(DirectedGraph,Origin);
    int DIndex = VertexName2Index(DirectedGraph,Destination);
    memset(Visit,0,sizeof(Visit));
    memset(PathResult,0,sizeof(PathResult));
    int i,j;
    for(i = 0; i < DirectedGraph->VertexNum; i ++)
    {
        Distance[i] = INT_MAX;
        PathResult[i] = OIndex;
    }

    struct VertexBodyNode *TmpPointer;
    
    TmpPointer = DirectedGraph -> VertexHeadNodeList[OIndex].Next;
    while(TmpPointer != NULL)
    {
        Distance[TmpPointer->VertexIndex] = TmpPointer -> ArcWeight;
        TmpPointer = TmpPointer -> Next;
    }
    
    int MinCost;
    int MinCostIndex = OIndex;
    for(i = 0;i < DirectedGraph->VertexNum-1;i ++)
    {
        MinCost = INT_MAX;

        for(j = 0;j < DirectedGraph->VertexNum;j ++)
        {
            if(Visit[j]==0 && Distance[j]<MinCost)
            {
                MinCostIndex = j;
                MinCost = Distance[j];
            }
        }
        
        Visit[MinCostIndex] = 1;
        
        TmpPointer = DirectedGraph -> VertexHeadNodeList[MinCostIndex].Next;
        while(TmpPointer != NULL)
        {
            if(Visit[TmpPointer->VertexIndex]==0 
            && MinCost+TmpPointer->ArcWeight<Distance[TmpPointer->VertexIndex])
            {
                Distance[TmpPointer->VertexIndex] = MinCost+TmpPointer->ArcWeight;
                PathResult[TmpPointer->VertexIndex] = MinCostIndex;
            }
            TmpPointer = TmpPointer -> Next;
        }
    }
    
    int TmpSearchIndex = DIndex;
    while(TmpSearchIndex != OIndex)
    {
        printf("%s <- ",DirectedGraph->VertexHeadNodeList[TmpSearchIndex].VertexName);
        TmpSearchIndex = PathResult[TmpSearchIndex];
    }
    if(DIndex != OIndex)
        printf("%s     Distance:%d\n",DirectedGraph->VertexHeadNodeList[OIndex].VertexName,Distance[DIndex]);
    else
        printf("%s     Distance:%d\n",DirectedGraph->VertexHeadNodeList[OIndex].VertexName,0);
}

int main()
{
    struct _Graph *G = UGCreat(8,5);

//    Travel(G);
    char Origin[MaxVertexNodeNameSize];
    char Destination[MaxVertexNodeNameSize];
    printf("Input Origin && Destination:\n");
    scanf("%s %s",Origin,Destination);
    DijkstraShortestPath(G,Origin,Destination);
    return 0;
}

/*
        beijing 18
        zhengzhou 10
        hefei 9
        nanjing 12
        guangzhou 14
        beijing zhengzhou 7
        beijing hefei 9
        beijing nanjing 8
        zhengzhou hefei 5
        hefei nanjing 3
        zhengzhou guangzhou 7
        hefei guangzhou 8
        nanjing guangzhou 6
*/