采用邻接矩阵表示法，创建无向图graph。实现功能:1、打印无向图void printUDN(AMGraph graph) 2、增加顶点Status InsertVex(AMGraph &G, int v)3、增加边Status DeleteVex(AMGraph &G, int v) 4、删除顶点Status InsertArc(AMGraph &G, int v, int w)5、删除边Status DeleteArc( AMGraph &G, int v, int w)

以下是基于邻接矩阵表示法的无向图的实现代码：

#include <iostream>
using namespace std;

const int MAX_VERTEX_NUM = 20;
const int INF = INT_MAX;

typedef char VertexType;
typedef int EdgeType;
typedef enum { UNVISITED, VISITED } VisitIf;

typedef struct {
    VertexType vexs[MAX_VERTEX_NUM]; // 存储顶点元素
    EdgeType arc[MAX_VERTEX_NUM][MAX_VERTEX_NUM]; // 存储边的权值
    int vexnum, arcnum; // 顶点数和边数
} AMGraph;

// 打印无向图
void printUDN(AMGraph graph) {
    for (int i = 0; i < graph.vexnum; i++) {
        for (int j = 0; j < graph.vexnum; j++) {
            if (graph.arc[i][j] == INF) {
                cout << "∞" << " ";
            } else {
                cout << graph.arc[i][j] << " ";
            }
        }
        cout << endl;
    }
}

// 增加顶点
int LocateVex(AMGraph graph, VertexType v) {
    for (int i = 0; i < graph.vexnum; i++) {
        if (v == graph.vexs[i]) {
            return i;
        }
    }
    return -1;
}

bool InsertVex(AMGraph &G, VertexType v) {
    if (G.vexnum == MAX_VERTEX_NUM) {
        return false;
    }
    G.vexs[G.vexnum] = v;
    for (int i = 0; i < G.vexnum; i++) {
        G.arc[i][G.vexnum] = INF;
        G.arc[G.vexnum][i] = INF;
    }
    G.vexnum++;
    return true;
}

// 删除顶点
bool DeleteVex(AMGraph &G, VertexType v) {
    int k = LocateVex(G, v);
    if (k == -1) {
        return false;
    }
    for (int i = 0; i < G.vexnum; i++) {
        if (i == k) {
            continue;
        }
        if (G.arc[i][k] != INF) {
            G.arc[i][k] = INF;
            G.arc[k][i] = INF;
            G.arcnum--;
        }
    }
    for (int i = k + 1; i < G.vexnum; i++) {
        G.vexs[i - 1] = G.vexs[i];
        for (int j = 0; j < G.vexnum; j++) {
            G.arc[j][i - 1] = G.arc[j][i];
        }
    }
    for (int i = 0; i < G.vexnum - 1; i++) {
        for (int j = k + 1; j < G.vexnum; j++) {
            G.arc[i][j - 1] = G.arc[i][j];
        }
    }
    G.vexnum--;
    return true;
}

// 增加边
bool InsertArc(AMGraph &G, VertexType v, VertexType w, EdgeType weight) {
    int i = LocateVex(G, v);
    int j = LocateVex(G, w);
    if (i == -1 || j == -1) {
        return false;
    }
    if (G.arc[i][j] != INF) {
        return false;
    }
    G.arc[i][j] = weight;
    G.arc[j][i] = weight;
    G.arcnum++;
    return true;
}

// 删除边
bool DeleteArc(AMGraph &G, VertexType v, VertexType w) {
    int i = LocateVex(G, v);
    int j = LocateVex(G, w);
    if (i == -1 || j == -1) {
        return false;
    }
    if (G.arc[i][j] == INF) {
        return false;
    }
    G.arc[i][j] = INF;
    G.arc[j][i] = INF;
    G.arcnum--;
    return true;
}

int main() {
    AMGraph graph;
    graph.vexnum = 0;
    graph.arcnum = 0;
    for (int i = 0; i < MAX_VERTEX_NUM; i++) {
        for (int j = 0; j < MAX_VERTEX_NUM; j++) {
            graph.arc[i][j] = INF;
        }
    }

    // 测试代码
    InsertVex(graph, 'A');
    InsertVex(graph, 'B');
    InsertVex(graph, 'C');
    InsertVex(graph, 'D');
    InsertArc(graph, 'A', 'B', 3);
    InsertArc(graph, 'A', 'C', 4);
    InsertArc(graph, 'B', 'C', 5);
    InsertArc(graph, 'B', 'D', 6);
    InsertArc(graph, 'C', 'D', 7);
    printUDN(graph);

    DeleteVex(graph, 'C');
    printUDN(graph);

    DeleteArc(graph, 'B', 'D');
    printUDN(graph);

    return 0;
}

该代码中包含了打印无向图、增加顶点、删除顶点、增加边、删除边等操作。在测试代码中，我们先增加了4个顶点，然后增加了5条边，接着删除了一个顶点和一条边，最后打印了无向图。