由邻接表构建的无向图输出给定顶点的简单回路_采用邻接表的存储结构,编写一个求无向图给定顶点的简单回路

作者：知新_RL | 2024-07-23 17:00:04

踩

采用邻接表的存储结构,编写一个求无向图给定顶点的简单回路

函数实现：

int pathnum = 0;
int path[MaxSize];
int j = 0;
int start;
void findcircle(ALGraph* G, int v1)
{
   EdgeNode* p;
   if(pathnum == 0)
       start = v1;
   int nextadj;
   path[j++] = v1;
   visited[v1] = 1;
   p = G->adjlist[v1].firstarc;
   while (p!=NULL)
   {
       nextadj = p->dest;
       if (nextadj == start && pathnum > 2)//成环了
       {
           for (int i = 0; i < j; i++)
               printf("%c ", G->adjlist[path[i]].VertexName);
           printf("%c\n", G->adjlist[start].VertexName);
       }
       else if(!visited[nextadj])//没有成环
       {
           pathnum++;
           findcircle(G, nextadj);
           j--;
           pathnum--;
           if (pathnum > 0)
               visited[nextadj] = 0;
       }
       p = p->next;
   }
}

全部代码：

#include <stdlib.h>
#include <stdio.h>
#include<conio.h>

#define MaxVerNum 100
#define MaxSize 100
int visited[MaxSize];

typedef struct enode //边的节点结构类型
{
int dest;//终点
struct enode* next;
}EdgeNode;

typedef struct VertexNode //头结点结构类型
{
char VertexName;
EdgeNode* firstarc;
}VERTEXNODE;

typedef struct
{
VERTEXNODE adjlist[MaxVerNum];
int n, e;//n-顶点，e-边
}ALGraph;

ALGraph g1;

ALGraph* CreateGraphList(ALGraph* g)
{
   int i, k, w, v;
   int n, e;
   EdgeNode* p;
   g = (ALGraph*)malloc(sizeof(ALGraph));
   printf("请输入有向图的顶点与边:");
   scanf_s("%d,%d", &n, &e);
   g->n = n;
   g->e = e;
   for (i = 0; i < n; i++)//头结点初始化
       g->adjlist[i].firstarc = NULL;
   printf("请输入%d个顶点:\n", n);
   for (i = -1; i < n; i++)
       scanf_s("%c", &g->adjlist[i].VertexName, 20);
   for (i = 0; i < e; i++)
   {
       printf("请输入第%d条边:", i + 1);
       scanf_s("%d,%d", &k, &w);
       EdgeNode* newnode;
       //有向图的建立
       newnode = (EdgeNode*)malloc(sizeof(EdgeNode));
       newnode->dest = w;
       newnode->next = g->adjlist[k].firstarc;
       g->adjlist[k].firstarc = newnode;
       newnode = (EdgeNode*)malloc(sizeof(EdgeNode));
       newnode->dest = k;
       newnode->next = g->adjlist[w].firstarc;
       g->adjlist[w].firstarc = newnode;
   }
   return g;
}

int main()
{
   ALGraph* g = &g1;
   g = CreateGraphList(g);
   for (int i = 0; i < g->n; i++)
       visited[i] = 0;
   int x;
   printf("请输入简单回路的起始点：");
   scanf_s("%d", &x);
   printf("简单回路:\n");
   for (int i = 0; i < g->n; i++)
       visited[i] = 0;
   findcircle(g,x);
   return 1;
}

声明：本文内容由网友自发贡献，不代表【wpsshop博客】立场，版权归原作者所有，本站不承担相应法律责任。如您发现有侵权的内容，请联系我们。转载请注明出处：https://www.wpsshop.cn/w/知新_RL/article/detail/870785