数据结构例程——拓扑排序

#include <stdio.h>
#include <malloc.h>
#include "graph.h"

void TopSort(ALGraph *G)
{
int i,j;
int St[MAXV],top=-1;            //栈St的指针为top
ArcNode *p;
for (i=0; i<G->n; i++)          //入度置初值0
G->adjlist[i].count=0;
for (i=0; i<G->n; i++)          //求所有顶点的入度
{
p=G->adjlist[i].firstarc;
while (p!=NULL)
{
G->adjlist[p->adjvex].count++;
p=p->nextarc;
}
}
for (i=0; i<G->n; i++)
if (G->adjlist[i].count==0)  //入度为0的顶点进栈
{
top++;
St[top]=i;
}
while (top>-1)                  //栈不为空时循环
{
i=St[top];
top--;              //出栈
printf("%d ",i);            //输出顶点
p=G->adjlist[i].firstarc;   //找第一个相邻顶点
while (p!=NULL)
{
j=p->adjvex;
G->adjlist[j].count--;
if (G->adjlist[j].count==0)//入度为0的相邻顶点进栈
{
top++;
St[top]=j;
}
p=p->nextarc;       //找下一个相邻顶点
}
}
}

int main()
{
ALGraph *G;
int A[7][7]=
{
{0,0,1,0,0,0,0},
{0,0,0,1,1,0,1},
{0,0,0,1,0,0,0},
{0,0,0,0,1,1,0},
{0,0,0,0,0,0,0},
{0,0,0,0,0,0,0},
{0,0,0,0,0,1,0}
};
ArrayToList(A[0], 7, G);
DispAdj(G);
printf("\n");
printf("拓扑序列:");
TopSort(G);
printf("\n");
return 0;
}