深度优先搜索遍历连通图的递归算法

//深度优先搜索遍历连通图的递归算法
#include <iostream>
using namespace std;

#define MVNun 100
typedef char VerTexType;
typedef int ArcType;

typedef struct {
    VerTexType vexs[MVNun];
    ArcType arcs[MVNun][MVNun];
    int vexnum, arcnum;
}Graph;

bool visited[MVNun];
int FirstAdjVex(Graph G, int v);
int NextAdjVex(Graph G, int v, int w);

int LocateVex(Graph G, VerTexType v) {
    for (int i = 0;i < G.vexnum;++i) {
        if (G.vexs[i] == v)
            return i;
    }
    return -1;
}

void CreateUDN(Graph& G) {
    int i, j, k;
    cout << "请输入总顶点数，总边数 , 以空格隔开:";
    cin >> G.vexnum >> G.arcnum;
    cout << endl;
    cout << "输入点的名称，如 a：" << endl;

    for (i = 0;i < G.vexnum;++i) {
        cout << "请输入第" << (i + 1) << "请输入第";
        cin >> G.vexs[i];
    }
    cout << endl;

    for (i = 0;i < G.vexnum;++i)
        for (j = 0;j < G.vexnum;++j)
            G.arcs[i][j] = 0;
    cout << "输入边依附的顶点，如：a b" << endl;
    for (k = 0;k < G.arcnum;++k) {
        VerTexType v1, v2;
        cout << "请输入第" << (k + 1) << "条边依附的顶点:";
        cin >> v1 >> v2;
        i = LocateVex(G, v1);
        j = LocateVex(G, v2);
        G.arcs[j][i] = G.arcs[i][j] = 1;
    }
}

void DFS(Graph G, int v) {
    cout << G.vexs[v] << "    ";  visited[v] = true;
    int w;
    for (w = FirstAdjVex(G, v); w >= 0; w = NextAdjVex(G, v, w))
        if (!visited[w]) DFS(G, w);
}

int FirstAdjVex(Graph G, int v) {
    int i;
    for (i = 0;i < G.vexnum;++i) {
        if (G.arcs[v][i] == 1 && visited[i] == false)
            return i;
    }
    return -1;
}

int NextAdjVex(Graph G, int v, int w) {
    int i;
    for (i = w;i < G.vexnum;++i) {
        if (G.arcs[v][i] == 1 && visited[i] == false)
            return i;
    }
    return -1;
}

int main() {
    cout << "深度优先搜索遍历连通图的递归算法";
    Graph G;
    CreateUDN(G);
    cout << endl;
    cout << "无向连通图G创建完成！" << endl;

    cout << "请输入遍历连通图的起始点：";
    VerTexType c;
    cin >> c;

    int i;
    for (i = 0;i < G.vexnum;++i) {
        if (c == G.vexs[i])
            break;
    }
    cout << endl;
    while (i >= G.vexnum) {
        cout << "该点不存在，请重新输入！" << endl;
        cout << "请输入遍历连通图的起始点：";
        cin >> c;
        for (i = 0;i < G.vexnum;++i) {
            if (c == G.vexs[i]) {
                break;
            }
        }
    }
    cout << "深度优先搜索遍历连通图结果：" << endl;
    DFS(G, i);

    cout << endl;
    return 0;
}