图的基本算法实现（邻接矩阵与邻接表两种方法）

一、无向图

1 无向图——邻接矩阵

测试环境：VS2008

#include "stdafx.h"
#include <stdlib.h>
#include <malloc.h>
#define MAX_VEX 20
#define INFINITY 65535
int *visited;
struct _node
{
    int vex_num;
    struct _node *next;
};
typedef struct _node node, *pnode;
struct _graph
{
    char *vexs;
    int arcs[MAX_VEX][MAX_VEX];
    int vexnum, arcnum;
};
typedef struct _graph graph, *pgraph;
int locate(graph g, char ch)
{
    int i;
    for(i=1; i<=g.vexnum; i++)
        if(g.vexs[i]==ch)
            return i;
    return -1;
}
graph create_graph()
{
    int i, j, w, p1, p2;
    char ch1, ch2;
    graph g;
    printf("Enter vexnum arcnum: ");
    scanf("%d %d", &g.vexnum, &g.arcnum);
    getchar();
    for(i=1; i<=g.vexnum; i++)
        for(j=1; j<g.vexnum; j++)
            g.arcs[i][j]=INFINITY;
    g.vexs=(char *)malloc(sizeof(char));
    printf("Enter %d vexnum.../n", g.vexnum);
    for(i=1; i<=g.vexnum; i++)
    {
        printf("vex %d: ", i);
        scanf("%c", &g.vexs[i]);
        getchar();
    }
    printf("Enter %d arcnum.../n", g.arcnum);
    for(i=1; i<=g.arcnum; i++)
    {
        printf("arc %d: ", i);
        scanf("%c %c %d", &ch1, &ch2, &w);
        getchar();
        p1=locate(g, ch1);
        p2=locate(g, ch2);
        g.arcs[p1][p2]=g.arcs[p2][p1]=w;
    }
    return g;
}
int firstvex_graph(graph g, int i)
{
    int k;
    if(i>=1 && i<=g.vexnum)
        for(k=1; k<=g.vexnum; k++)
            if(g.arcs[i][k]!=INFINITY)
                return k;
    return -1;
}
int nextvex_graph(graph g, int i, int j)
{
    int k;
    if(i>=1 && i<=g.vexnum && j>=1 && j<=g.vexnum)
        for(k=j+1; k<=g.vexnum; k++)
            if(g.arcs[i][k]!=INFINITY)
                return k;
    return -1;
}
void dfs(graph g, int i)
{
    int k, j;
    if(!visited[i])
    {
        visited[i]=1;
        printf("%3c", g.vexs[i]);
        for(j=firstvex_graph(g, i); j>=1; j=nextvex_graph(g, i, j))
            if(!visited[j])
                dfs(g, j);
    }
}
void dfs_graph(graph g)
{
    int i;
    visited=(int *)malloc((g.vexnum+1)*sizeof(int));
    for(i=1; i<=g.vexnum; i++)
        visited[i]=0;
    for(i=1; i<g.vexnum; i++)
        if(!visited[i])
            dfs(g, i);
}
int _tmain(int argc, _TCHAR* argv[])
{
    graph g;
    g=create_graph();
    printf("DFS: ");
    dfs_graph(g);
    printf("/n");
    return 0;
}

运行结果：

       

==========================================================

2 无向图—— 邻接表

测试环境：VS2008

#include "stdafx.h"
#include <stdlib.h>
#include <malloc.h>
#define MAX_VEX 20
int *visited;
typedef struct _ArcNode
{
    int ivex; /* next ivex */
    struct _ArcNode *nextarc; /* next node */
    int *info; /* arc weight */
};
typedef struct _ArcNode ArcNode, *pArcNode;
struct _VNode
{
    char adjvex; /* note vex */
    ArcNode *firstarc;
};
typedef struct _VNode VNode;
struct _ALGraph
{
    VNode AdjList[MAX_VEX];
    int vexnum, arcnum;
    int kink;
};
typedef struct _ALGraph ALGraph;
int locate(ALGraph g, char ch)
{
    int i;
    for(i=1; i<=g.vexnum; i++)
        if(g.AdjList[i].adjvex==ch)
            return i;
    return -1;
}
ALGraph create_graph()
{
    int i, j, w, p1, p2;
    char ch1, ch2;
    pArcNode pnode, pnode1, pnode2;
    ALGraph g;
    printf("Enter vexnum arcnum: ");
    scanf("%d %d", &g.vexnum, &g.arcnum);
    getchar();

    printf("Enter %d vexnum.../n", g.vexnum);
    for(i=1; i<=g.vexnum; i++)
    {
        printf("vex %d: ", i);
        scanf("%c", &g.AdjList[i].adjvex);
        getchar();
        g.AdjList[i].firstarc=NULL;
    }
    printf("Enter arc.../n");
    for(i=1; i<=g.arcnum; i++)
    {
        printf("arc %d: ", i);
        scanf("%c %c", &ch1, &ch2);
        getchar();
        p1=locate(g, ch1);
        p2=locate(g, ch2);
        pnode1=(pArcNode)malloc(sizeof(ArcNode));
        pnode2=(pArcNode)malloc(sizeof(ArcNode));
        pnode1->ivex=p2; /* next ivex */
        pnode1->nextarc=g.AdjList[p1].firstarc;
        g.AdjList[p1].firstarc=pnode1;
        pnode2->ivex=p1; /* next ivex */
        pnode2->nextarc=g.AdjList[p2].firstarc;
        g.AdjList[p2].firstarc=pnode2;
    }
    return g;
}
int firstvex_graph(ALGraph g, int i)
{
    int k;
    if(i>=1 && i<=g.vexnum)
        if(g.AdjList[i].firstarc)
            return g.AdjList[i].firstarc->ivex;
    return -1;
}
int nextvex_graph(ALGraph g, int i, int k)
{
    pArcNode pnode;
    if(i>=1 && i<=g.vexnum && k>=1 && k<=g.vexnum)
    {
        pnode=g.AdjList[i].firstarc;
        while(pnode->nextarc)
        {
            k=pnode->nextarc->ivex;
            if(!visited[k])
                return k;
            else
                pnode=pnode->nextarc;
        }
    }
    return -1;
}
void dfs(ALGraph g, int i)
{
    int k;
    if(!visited[i])
    {
        visited[i]=1;
        printf("%c", g.AdjList[i].adjvex);
        for(k=firstvex_graph(g, i); k>=1; k=nextvex_graph(g, i, k))
            if(!visited[k])
                dfs(g, k);
    }
}
void dfs_graph(ALGraph g)
{
    int i;
    visited=(int *)malloc((g.vexnum+1)*sizeof(int));
    for(i=1; i<=g.vexnum; i++)
        visited[i]=0;
    for(i=1; i<=g.vexnum; i++)
        if(!visited[i])
            dfs(g, i);
}
int _tmain(int argc, _TCHAR* argv[])
{
    ALGraph g;
    g=create_graph();
    dfs_graph(g);
    printf("/n");
    return 0;
}

运行结果：

      

原谅链接：http://blog.csdn.net/Sunboy_2050/article/details/5683488