圖的拓撲排序（鄰接表）

#include <stdio.h>
#include <stdlib.h>
#define Max_Vertex_Num 100
#define STACK_SIZE 30

typedef struct ArcNode{
    int adjvex; //此題用不到
    struct ArcNode *nextarc;//下一個節點
    int weight;//權重-此題用不到
}ArcNode;
/*表頭節點*/
typedef struct VNode{
    int vertex;//表頭數組的數據
    ArcNode *firstarc;//表頭數組的表頭節點域
}VNode;
typedef VNode Adjlist[Max_Vertex_Num];//VNode構成的表頭節點數組
/*整個鄰接表*/
typedef struct{
    Adjlist adjlist;//每個定點後面的鏈表，記錄關聯點
    int vexnum,arcnum;//頂點數和邊數
}ALGraph;
/*棧*/
typedef struct{
    int *base;
    int *top;  //棧頂指針
    int size;
}seqStack;
int InitStack(seqStack *s){
    s->base = (int *)malloc(STACK_SIZE* sizeof(seqStack));//動態分配30個單位的stack
    //省略是否空間滿
    s->top = s->base;//棧頂和棧尾相同，棧裏面沒有元素
    s->size = STACK_SIZE;
    return 1;
}
int Push(seqStack *s,int x){

    *s->top = x;
    s->top++;
    return 1;
}
int Pop(seqStack *s,int *x){
    if(s->top == s->base)return 0;
    else{
        s->top--;
        *x = *s->top;
        return 1;
    }
}
int GetTop(seqStack *s, int *x){
    if(s->top==s->base)
        return 0;
    else{
        *x=*(s->top-1);
        return 1;
    }
}
int IsEmpty(seqStack *s){
    if(s->top==s->base){
        return 1;
    }else{
        return 0;
    }
}

void FindIndegree(ALGraph *G,int indegree[])
{
    int i;
    ArcNode *p;
    for(i = 0;i<G->vexnum ;i++)
    {
        indegree[i]=0;
    }

    for(i = 0;i<G->vexnum ;i++)
    {
        p = G->adjlist[i].firstarc;
        while(p){
            indegree[p->adjvex]++;
            p=p->nextarc;
        }/*while*/
    }/*for*/

}/*end*/
void TopLogicalSort(ALGraph *G){
    int i,k;
    int count;
    ArcNode *p;
    int indegree[G->vexnum];
    FindIndegree(G,indegree);
    seqStack s;
    InitStack(&s);
    for(i = 0;i<G->vexnum;i++)
    {
        //入度爲0的頂點入棧
        if(indegree[i]==0){
            Push(&s,i);
        }
    }
    count =0;
    while(!IsEmpty(&s)){
        Pop(&s,&i);
        printf("%d ",G->adjlist[i].vertex);
        ++count;
        for(p=G->adjlist[i].firstarc;p;p=p->nextarc)
        {
            k=p->adjvex;
            if((--indegree[k]==0)){
                Push(&s,k);
            }/*if*/
        }/*for*/
    }/*while*/


    /*迴路異常*/
    if(count<G->vexnum){
        exit(0);
    }



}

int LocateVex(ALGraph *G,int u){
    int i;
    for(i = 0; i<G->vexnum;++i)
    {
        if(G->adjlist[i].vertex == u)
        {
            return i;
        }
    }
    return -1;
}

void CreateALGraph(ALGraph *G,int gType)
{
    ArcNode *p;
    int i,j,k;
    int v1,v2;

    scanf("%d,%d",&G->vexnum,&G->arcnum); //輸入頂點數和邊數

    if(gType==0)
    {
        for(k=0;k<G->vexnum;k++)
        {
            G->adjlist[k].vertex = k;
            G->adjlist[k].firstarc = NULL;
        }
        k = 0;
        while(k<G->arcnum){
            scanf("%d,%d",&v1,&v2);
            k++;
            i = LocateVex(G,v1);
            j = LocateVex(G,v2);
            /*給第i的表頭添加數據是j的節點*/
            p=(ArcNode*)malloc(sizeof(ArcNode));
            p->adjvex = j;
            p->nextarc = G->adjlist[i].firstarc;
            G->adjlist[i].firstarc = p;

            /*給第j的表頭添加數據是i的節點*/
            p=(ArcNode*)malloc(sizeof(ArcNode));
            p->adjvex = i;
            p->nextarc = G->adjlist[j].firstarc;
            G->adjlist[j].firstarc = p;
        }
    }else{
        for(k=0;k<G->vexnum;k++)
        {
            G->adjlist[k].vertex = k;
            G->adjlist[k].firstarc = NULL;
        }
        k = 0;
        while(k<G->arcnum){
            scanf("%d,%d",&v1,&v2);
            k++;
            i = LocateVex(G,v1);
            j = LocateVex(G,v2);
            /*給第i的表頭添加數據是j的節點——有向圖，不需要給j添加i數據的節點了*/
            p=(ArcNode*)malloc(sizeof(ArcNode));
            p->adjvex = j;
            p->nextarc = G->adjlist[i].firstarc;
            G->adjlist[i].firstarc = p;
        }
    }
}

int main()
{
    ALGraph G;
    CreateALGraph(&G,1);
    TopLogicalSort(&G);
    return 0;
}