数据结构——邻接表表示的图的拓扑排序算法

#include <iostream>using namespace std;#include <stdio.h>#include <stdlib.h>#define OK 1#define NULL 0#define MAX_VERTEX_NUM 20 // 最大顶点数typedef char VertexType;typedef int VRType;typedef int InforType;typedef int indegree[MAX_VERTEX_NUM];typedef struct ArcNode{        int adjvex;   //该边所指的顶点的位置        struct ArcNode *nextarc;   //指向下一条边的指针        int weight;  //边的权}ArcNode;   //表的结点typedef struct VNode{        VertexType data;        //顶点信息（如数据等）        ArcNode *firstarc;        //指向第一条依附该顶点的边的弧指针}VNode, AdjList[MAX_VERTEX_NUM];   //头结点typedef struct ALGraph{        AdjList vertices;        int vexnum, arcnum;   //图的当前顶点数和弧数}ALGraph;//初始化图void init_ALGraph(ALGraph &g){    g.arcnum=0;    g.vexnum=0;}//返回顶点v在顶点向量中的位置int LocateVex(ALGraph &G, char v){        int i;        for(i = 0; v != G.vertices[i].data && i < G.vexnum; i++)                ;        if(i >= G.vexnum)                return -1;        return i;}//增加节点void add_vex(ALGraph &G){        cout<<"输入有向图顶点数: "<<endl;        cin>>G.vexnum;        //getchar();    //吃回车        cout<<"输入顶点信息:"<<endl;        for(int i = 0; i < G.vexnum; i++)        {                cin>>G.vertices[i].data;   //构造顶点向量                G.vertices[i].firstarc = NULL;                //getchar();        }}//增加边void add_arc(ALGraph &G, indegree indegree){        ArcNode *s;        ArcNode *p;        for(int k=0; k<G.vexnum; k++)            indegree[k]=0;        cout<<"输入有向图边数: "<<endl;        cin>>G.arcnum;        char v1, v2;        cout<<"输入边信息:"<<endl;        for(k = 0; k < G.arcnum; k++)        {                cin>>v1>>v2;                int i = LocateVex(G, v1);                int j = LocateVex(G, v2);    //确定v1 , v2在G中的位置                ++indegree[j];        //点j的入度增加1                s = (ArcNode*) malloc (sizeof(ArcNode));                s->adjvex = j;   //该边所指向的顶点的位置为j                s->nextarc = NULL;                if(!G.vertices[i].firstarc)                {                    G.vertices[i].firstarc=s;                }                else                {                    for(p = G.vertices[i].firstarc; p->nextarc; p = p->nextarc)                            ;                    p->nextarc=s;                }        }}//构造邻接链表void CreateUDN(ALGraph &G, indegree indegree){        add_vex(G);        //增加节点        add_arc(G,indegree);        //增加边        }void PrintAdjList(ALGraph &G){        int i;        ArcNode *p;        cout<<"编号    顶点    邻点编号"<<endl;        for(i = 0; i < G.vexnum; i++)        {                cout<<"  "<<i<<"       "<<G.vertices[i].data<<"      ";                for(p = G.vertices[i].firstarc; p; p = p->nextarc)                        cout<<p->adjvex<<"  ";                cout<<endl;        }}//拓扑排序int TopologicalSort(ALGraph &g, indegree indegree){    //若G无回路，则输出拓扑排序序列并返回1，若有回路返回0。    ArcNode *q;    int i,k;    int gettop;    int *stack;            //建栈将入度为0的顶点入栈    stack=(int *)malloc( g.vexnum*sizeof(int) );    int top=0;    for(i = 0; i<g.vexnum; i++)                if(0 == indegree[i])        //将入度为0的顶点入栈            stack[++top]=i;    int count=0;    while(top!=0)    {        gettop=stack[top--];        cout<<g.vertices[gettop].data<<"-->";        count++;        //输出i号顶点，并计数        for(q = g.vertices[gettop].firstarc; q; q = q->nextarc)        {            k=q->adjvex;            if( !(--indegree[k]) )        //将i号顶点的邻接点的入度减1，如果减1后为0，则入栈                stack[++top]=k;        }//for    }//while    cout<<endl;    if(count < g.vexnum)        return 1;    else        return 0;}int main(){        ALGraph G;        indegree indegree;        init_ALGraph(G);    //初始化图        CreateUDN(G, indegree);        //创建图        PrintAdjList(G);    //打印图        TopologicalSort(G, indegree);        return 0;}