图-基础

#include<stdio.h>
#include<stdlib.h>
#include<vector>
#include<iostream>
#include<assert.h>
using namespace std;

//稠密图 - 邻接矩阵
class DenseGraph {
private:
    int n, m;  //顶点，边
    bool directed;   //有向或无向
    vector<vector<bool>> g;   //邻接矩阵

public:
    DenseGraph(int n, bool directed) {
        this->n = n;
        this->m = 0;
        this->directed = directed;
        for (int i = 0; i < n; i++) {
            g.push_back(vector<bool>(n, false));
        }
    }
    ~DenseGraph()
    {

    }
    int V() { return n; }
    int E() { return m; }

    void addEdge(int v, int w) {
        assert(v >= 0 && v < n);
        assert(w >= 0 && w < n);

        if (hasEdge(v, w))
            return;   //若已经有边，直接return

        g[v][w] = true;  //有向图

        if (!directed) {
            //无向图
            g[w][v] = true;
        }
        m++;
    }
    bool hasEdge(int v, int w) {
        //判断v和w之间是否已经存在边 （不包括平行边）
        assert(v >= 0 && v < n);
        assert(w >= 0 && w < n);
        return g[v][w];  //返回为true或false
    }
};

#include<stdio.h>
#include<stdlib.h>
#include<vector>
#include<iostream>
#include<assert.h>
using namespace std;

//稀疏图 - 邻接表
class SparseGraph {
private:
    int n, m;  //顶点，边
    bool directed;   //有向或无向
    vector<vector<int>> g;   // 邻接表 每一行存储的是顶点编号

public:
    SparseGraph(int n, bool directed) {
        //构造函数来初始化
        this->n = n;
        this->m = 0;
        this->directed = directed;
        for (int i = 0; i < n; i++) {
            g.push_back(vector<int>() );
        }
    }
    ~SparseGraph()
    {

    }
    int V() { return n; }
    int E() { return m; }

    void addEdge(int v, int w) {
        assert(v >= 0 && v < n);
        assert(w >= 0 && w < n);

        if (hasEdge(v, w))
            return;   //若已经有边，直接return

        g[v].push_back(w);  //v和w相连

        if (v!=w && !directed) {
            //无向图
            g[w].push_back(v);
        }
        m++;
    }
    bool hasEdge(int v, int w) {
        //判断v和w之间是否存在边
        assert(v >= 0 && v < n);  //判断v和w不越界
        assert(w >= 0 && w < n);

        for (int i = 0; i < g[v].size();i++) {
            if (g[v][i] == w)
                return true;
            return false;
        }
        return g[v][w];  //返回为true或false
    }
};