指针实现邻接表模板

自己写的一个无向图邻接表，edge代表邻接的节点，head代表邻接表主体节点。
不是很喜欢用数组建表，主要是因为数组建表虽然实现简单，但是理解略显复杂，这个方面可以参考朝夕的博客。

struct edge
{
    edge *next;
    int num;
    int len;
};

edge eg[100000];

struct head
{
    edge *next;
    int num;
};

head h[100000];

void IniList(int n)
{
    int i;
    
    for (i = 1; i <= n; i++)
    {
        h[i].next = NULL;
        h[i].num = i;
    }
}

void CreatList(int n, int m)
{
    int i;
    int x, y, leng;
    
    for (i = 0; i < m; i++)
    {
        cin >> x >> y >> leng;
        
        edge *p1, *p2;
        
        p1 = new edge;
        p1 -> next = NULL;
        p1 -> num = y;
        p1 -> len = leng;
        
        p2 = new edge;
        p2 -> next = NULL;
        p2 -> num = x;
        p2 -> len = leng;
        
        edge *p3, *p4;
        
        p3 = h[x].next;
        
        if (p3 == NULL) {
            h[x].next = p1;
        }
        
        else
        {
            while (p3 -> next != NULL) {
                p3 = p3 -> next;
            }
            
            p3 -> next = p1;
        }
        
        p4 = h[y].next;
        
        if (p4 == NULL) {
            h[y].next = p2;
        }
        
        else
        {
            while (p4 -> next != NULL) {
                p4 = p4 -> next;
            }
            
            p4 -> next = p2;
        }
    }
}

void PrintList(int n)
{
    int i;
    edge *p;
    
    for (i = 1; i <= n; i++)
    {
        p = h[i].next;
        
        cout << "Node:" << h[i].num << endl;
        
        while (p != NULL) {
            cout << p -> num << " " << p -> len << " ";
            p = p -> next;
        }
        
        cout << endl;
    }
}

上面的CreatList是在函数内部输入，并且是为无向图服务的(分别在h[x]和h[y]都增加了节点)，如果是无向图的话也可以在外部调用两次下面的函数：CreatList(x, y, leng); CreatList(y, x, leng);

void CreatList(int x, int y, int leng)
{
    edge *p1, *p2;
    
    p1 = new edge;
    p1 -> next = NULL;
    p1 -> num = y;
    p1 -> len = leng;
    
    p2 = h[x].next;
    
    if (p2 == NULL) {
        h[x].next = p1;
    }
    
    else
    {
        while (p2 -> next != NULL) {
            p2 = p2 -> next;
        }
        
        p2 -> next = p1;
    }
}

2016/12/18