拓扑排序（Topological）

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<stdlib.h>
#include<stack>
using namespace std;
#define MAX 20
typedef struct node
{
    struct node * nextarc;
    char Info;
}ArcNode, *pArcNode;
typedef struct
{
    int VerCount;//顶点数目
    int ArcCount;    //弧的数目
    pArcNode Adj;
}AdjList, *pAdjList;
void CreatAdj(pAdjList myAdjList,int *sign)
{
    int i, j;
    char tail;
    pArcNode p, q;
    
    
    printf("Please input the num of Vertex:");//顶点个数
    scanf("%d", &myAdjList->VerCount);

    printf("Pleaase input the num of Arc");//弧的个数
    scanf("%d", &myAdjList->ArcCount);

    myAdjList->Adj = (pArcNode)malloc(myAdjList->VerCount  *sizeof(ArcNode));
    for (i = 0; i < myAdjList->VerCount; i++)
        myAdjList->Adj[i].nextarc = NULL;

    printf("Please input the Graph: 
");
    printf("Please input all of the vertex:
");
    fflush(stdin);
    for (i = 0; i < myAdjList->VerCount; i++)
    {
        scanf("%c", &myAdjList->Adj[i].Info);
        fflush(stdin);
    }
    printf("Please input the Ver:
");
    for (i = 0; i < myAdjList->ArcCount; i++)
    {
        printf("Please input tail of Arc%d :", i);
        scanf("%c", &tail);
        p = (pArcNode)malloc(sizeof(ArcNode));
        p->nextarc = NULL;
        fflush(stdin);
        printf("Please input head of Arc%d :", i);
        scanf("%c", &p->Info);
        getchar();

        for (j = 0; j < myAdjList->VerCount; j++)
            if (myAdjList->Adj[j].Info == p->Info)
                    sign[j]++;

        for (j = 0; j < myAdjList->VerCount; j++)
        {
            if (myAdjList->Adj[j].Info == tail)
            {
                q = &myAdjList->Adj[j];
                while (q->nextarc != NULL)
                    q = q->nextarc;

                q->nextarc = p;
            }
        }

    }

}
void TopologicalSort(pAdjList myAdjList, int *sign)
{
    stack <ArcNode> S;
    ArcNode *temp;

    int s[10];
    int i, j;
    for (i = 0; i < myAdjList->VerCount; i++)
        s[i] = sign[i];

    for (i = 0; i < myAdjList->VerCount; i++)
    {
        if (s[i] == 0)
        {
            S.push(myAdjList->Adj[i]);
            s[i] = -1;
        }
    }
    while (!S.empty())
    {
        
        for (i = 0; i < myAdjList->VerCount; i++)
            if (myAdjList->Adj[i].Info == S.top().Info)
                temp = &myAdjList->Adj[i];
        S.pop();
        printf("%c", temp->Info);
        while (temp->nextarc != NULL)
        {
            for ( j = 0; j < myAdjList->VerCount; j++)
            {
                if (myAdjList->Adj[j].Info == temp->nextarc->Info)
                {
                    s[j]--;
                    if (s[j] == 0)
                    {
                        S.push(myAdjList->Adj[j]);
                        s[j] = -1;
                    }
                    
                }
            
            }
            temp = temp->nextarc;
        }
        
    }
}
int main()
{
    AdjList myAdjList;
    int sign[10];
    for (int i = 0; i < 10; i++)
        sign[i] = 0;
    CreatAdj(&myAdjList,sign);
    TopologicalSort(&myAdjList, sign);
    
    
    system("pause");
    return 0;
}

栈操作。