output adjacent node by both dense && sparse graph finished

Author: Zu3zz

.vscode/settings.json

@@ -1,4 +1,7 @@
 {
   "python.linting.pylintEnabled": true,
-  "python.pythonPath": "/Users/3zz/anaconda3/bin/python"
+  "python.pythonPath": "/Users/3zz/anaconda3/bin/python",
+  "files.associations": {
+    "vector": "cpp"
+  }
 }

graph-theory/02-iterator-near-node/DenseGraph.h

@@ -0,0 +1,77 @@
+#include <iostream>
+#include <cassert>
+#include <vector>
+
+using namespace std;
+
+class DenseGraph{
+private:
+  int n, m;               // 节点数和边数
+  bool directed;          // 是否为有向图
+  vector<vector<bool> > g; // 图的具体数据
+
+public:
+  // 构造函数
+  DenseGraph(int n, bool directed){
+    assert(n >= 0);
+    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;
+    }
+    g[v][w] = true;
+    if(!directed){
+      g[w][v] = true;
+    }
+    m++;
+  }
+  
+  bool hasEdge(int v, int w){
+    assert(v >= 0 && v <n);
+    assert(w >= 0 && w < n);
+    return g[v][w];
+  }
+
+  class adjIterator{
+  private:
+    DenseGraph &G;
+    int v;
+    int index;
+  public:
+    adjIterator(DenseGraph &graph, int v): G(graph){
+      assert( v>=0 && v< G.n);
+      this->v = v;
+      this->index = -1;
+    }
+    ~adjIterator(){}
+    // 返回图G中与顶点v相连接的第一个顶点
+    int begin(){
+      // 索引从-1开始, 因为每次遍历都需要调用一次next()
+      index = -1;
+      return next();
+    }
+    int next(){
+      for(index +=1;index < G.V();index++)
+        if(G.g[v][index])
+          return index;
+        return -1;
+    }
+    bool end(){
+      return index >= G.V();
+    }
+  };
+};

graph-theory/02-iterator-near-node/SparseGraph.h

@@ -0,0 +1,90 @@
+#include <iostream>
+#include <cassert>
+#include <vector>
+
+using namespace std;
+
+class SparseGraph
+{
+private:
+  int n, m;              // 节点数和边数
+  bool directed;         // 是否为有向图
+  vector<vector<int> > g; // 图的具体连接情况
+
+public:
+  // 构造函数
+  SparseGraph(int n, int directed)
+  {
+    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 W() { return m; }
+
+  void addEdge(int v, int w)
+  {
+    assert(v >= 0 && v < n);
+    assert(w >= 0 && w < n);
+    g[v].push_back(w);
+    // 考虑自环边
+    if (v != w && !directed)
+    {
+      g[w].push_back(v);
+    }
+    m++;
+  }
+  // 需要遍历 O(n)
+  bool hasEdge(int v, int w)
+  {
+    assert(v >= 0 && v < n);
+    assert(w >= 0 && w < n);
+    for (int i = 0; i < g[v].size(); i++)
+      if (g[v][i] == w)
+        return true;
+    return false;
+  }
+
+  class adjIterator
+  {
+  private:
+    SparseGraph &G;
+    int v;
+    int index;
+
+  public:
+    adjIterator(SparseGraph &graph, int v) : G(graph)
+    {
+      this->v = v;
+      this->index = 0;
+    }
+    int begin()
+    {
+      index = 0;
+      if (G.g[v].size())
+      {
+        return G.g[v][index];
+      }
+      return -1;
+    }
+    int next()
+    {
+      index++;
+      if (index < G.g[v].size())
+      {
+        return G.g[v][index];
+      }
+      return -1;
+    }
+    bool end()
+    {
+      return index >= G.g[v].size();
+    }
+  };
+};

graph-theory/02-iterator-near-node/main.cpp

@@ -0,0 +1,58 @@
+#include <iostream>
+#include "SparseGraph.h"
+#include "DenseGraph.h"
+
+using namespace std;
+
+int main()
+{
+  int N = 20;
+  int M = 100;
+
+  srand(time(NULL));
+
+  // Sparse Graph
+  SparseGraph g1(N, false);
+  for (int i = 0; i < M; i++)
+  {
+    int a = rand() % N;
+    int b = rand() % N;
+    g1.addEdge(a, b);
+  }
+  // 输出邻接点
+  // O(E)
+  for (int v = 0; v < N; v++)
+  {
+    cout << v << " : ";
+    SparseGraph::adjIterator adj(g1, v);
+    for (int w = adj.begin(); !adj.end(); w = adj.next())
+    {
+      cout << w << " ";
+    }
+    cout << endl;
+  }
+  cout << endl;
+
+  // Dense Graph
+  DenseGraph g2(N, false);
+  for (int i = 0; i < M; i++)
+  {
+    int a = rand() % N;
+    int b = rand() % N;
+    g2.addEdge(a, b);
+  }
+  // 输出邻接点
+  // O(v^2)
+  for (int v = 0; v < N; v++)
+  {
+    cout << v << " : ";
+    DenseGraph::adjIterator adj(g2, v);
+    for (int w = adj.begin(); !adj.end(); w = adj.next())
+    {
+      cout << w << " ";
+    }
+    cout << endl;
+  }
+  cout << endl;
+  return 0;
+}