图的深度优先遍历的实现 c/c++ DFS

#include <iostream>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

using namespace std;

#define MAX 100

#define LENGTH(a) (sizeof(a) / sizeof(a[0]))

int visited[MAX];

typedef struct _graph{

char vexs[MAX];

int vexnum;

int edgnum;

int matrix[MAX][MAX];

}Graph,*PGgraph;

static int get_position(Graph g, char ch){

for(int i = 0;i<g.vexnum;i++){

if(ch == g.vexs[i])

return i;

}

return -1;

}

static char read_char(){

char ch;

while(!((((ch)>='a') && ((ch)<='z')) || (((ch)>='A') && ((ch)<='Z'))))

ch = getchar();

return ch;

}

Graph creat_graph(){

char c1,c2;

int v,e;

int p1,p2;

Graph pG;

cout<<"input number of vex > ";

cin>>v;

cout<<"input number of edge > ";

cin>>e;

//memset(pG,0,sizeof(Graph));

pG.vexnum = v;

pG.edgnum = e;

//Initialize vexs

for(int i=0; i<pG.vexnum;i++){

//pG.vexs[i] = read_char();

cin>>pG.vexs[i] ;

}

//Initialize edges

for(int i = 0;i < pG.edgnum; i++){

//c1 = read_char();

//c2 = read_char();

cin>>c1>>c2;

cout<<c1<<c2<<endl;

p1 = get_position(pG, c1);

p2 = get_position(pG, c2);

pG.matrix[p1][p2] = 1;

pG.matrix[p2][p1] = 1;

}

return pG;

}

static int next_vertex(Graph g, int v,int w){

if(v<0 || v>g.vexnum-1|| w<0 || w>(g.vexnum-1))   return -1;

for(int i=w+1; i < g.vexnum; i++){

if(g.matrix[v][i] == 1)  return i;

}

return -1;

}

static int first_vertex(Graph g, int v){

if(v<0 || v>g.vexnum-1)   return -1;

for(int i=0; i < g.vexnum; i++){

if(g.matrix[v][i] == 1)  return i;

}

return -1;

}

void DFS(Graph g, int i){

if(visited[i] == 0){

visited[i] = 1;

cout<<g.vexs[i]<<" ";

}

int w = first_vertex(g,i);

for(;w>=0; w = next_vertex(g,i,w)){

if(!visited[w]) DFS(g,w);

}

}

int main(int argc, const char * argv[]) {

for(int i = 0; i < MAX; i++){

visited[i] = 0;

}

Graph g;

g= creat_graph();

for(int i = 0; i< g.vexnum; i++){

if(!visited[i])         DFS(g,i);

}

return 0;

}