图的邻接表实现_LGraph

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邻接表是图的另一种有效的存储表示方法. 每个顶点u建立一个单链表, 链表中每个结点代表一条边<u, v>, 为边结点. 每个单链表相当于

邻接矩阵的一行.

adjVex域指示u的一个邻接点v, nxtArc指向u的下一个边结点. 如果是网, 增加一个w域存储边上的权值.

构造函数完成对一维指针数组a的动态空间存储分配, 并对其每个元素赋初值NULL. 析构函数首先释放邻接表中所有结点, 最后释放一维

指针数组a所占的空间.

包含的函数Exist(): 若输入的u, v无效, 则函数返回false. 否则从a[u]指示的边结点开始, 搜索adjVex值为v的边结点, 代表边<u, v>, 若搜索

成功, 返回true, 否则返回false.

函数Insert(): 若输入的u, v无效, 则插入失败, 返回Failure. 否则从a[u]指示的边开始, 搜索adjVex值为v的边结点, 若不存在这样的边结

点, 则创建代表边<u, v>的新边结点, 并将其插在由指针a[u]所指示的单链表最前面, 并e++. 否则表示<u, v>是重复边, 返回Duplicate.

函数Remove(): 若输入的u, v无效, 则删除失败, 返回Failure. 否则从a[u]指示的边开始, 搜索adjVex值为v的边结点, 若存在这样的边, 删

除边, e--, 返回Success. 否则表示不存边<u, v>, 返回NotPresent.

实现代码:

#include "iostream"
#include "cstdio"
#include "cstring"
#include "algorithm"
#include "queue"
#include "stack"
#include "cmath"
#include "utility"
#include "map"
#include "set"
#include "vector"
#include "list"
#include "string"
using namespace std;
typedef long long ll;
const int MOD = 1e9 + 7;
const int INF = 0x3f3f3f3f;
enum ResultCode { Underflow, Overflow, Success, Duplicate, NotPresent, Failure };
template <class T>
struct ENode
{
	ENode() { nxtArc = NULL; }
	ENode(int vertex, T weight, ENode *nxt) {
		adjVex = vertex;
		w = weight;
		nxtArc = nxt;
	}
	int adjVex;
	T w;
	ENode *nxtArc;
	/* data */
};
template <class T>
class Graph
{
public:
	virtual ~Graph() {}
	virtual ResultCode Insert(int u, int v, T &w) = 0;
	virtual ResultCode Remove(int u, int v) = 0;
	virtual bool Exist(int u, int v) const = 0;
	/* data */
};
template <class T>
class LGraph: public Graph<T>
{
public:
	LGraph(int mSize);
	~LGraph();
	ResultCode Insert(int u, int v, T &w);
	ResultCode Remove(int u, int v);
	bool Exist(int u, int v) const;
	int Vertices() const { return n; }
	void Output();
protected:
	ENode<T> **a;
	int n, e;
	/* data */
};
template <class T>
void LGraph<T>::Output()
{
	ENode<T> *q;
	for(int i = 0; i < n; ++i) {
		q = a[i];
		while(q) {
			cout << '(' << i << ' ' << q -> adjVex << ' ' << q -> w << ')';
			q = q -> nxtArc;
		}
		cout << endl;
	}
	cout << endl << endl;
}
template <class T>
LGraph<T>::LGraph(int mSize)
{
	n = mSize;
	e = 0;
	a = new ENode<T>*[n];
	for(int i = 0; i < n; ++i)
		a[i] = NULL;
}
template <class T>
LGraph<T>::~LGraph()
{
	ENode<T> *p, *q;
	for(int i = 0; i < n; ++i) {
		p = a[i];
		q = p;
		while(p) {
			p = p -> nxtArc;
			delete q;
			q = p;
		}
	}
	delete []a;
}
template <class T>
bool LGraph<T>::Exist(int u, int v) const
{
	if(u < 0 || v < 0 || u > n - 1 || v > n - 1 || u == v) return false;
	ENode<T> *p = a[u];
	while(p && p -> adjVex != v) p = p -> nxtArc;
	if(!p) return false;
	return true;
}
template <class T>
ResultCode LGraph<T>::Insert(int u, int v, T &w)
{
	if(u < 0 || v < 0 || u > n - 1 || v > n - 1 || u == v) return Failure;
	if(Exist(u, v)) return Duplicate;
	ENode<T> *p = new ENode<T>(v, w, a[u]);
	a[u] = p;
	e++;
	return Success;
}
template <class T>
ResultCode LGraph<T>::Remove(int u, int v)
{
	if(u < 0 || v < 0 || u > n - 1 || v > n - 1 || u == v) return Failure;
	ENode<T> *p = a[u], *q = NULL;
	while(p && p -> adjVex != v) {
		q = p;
		p = p -> nxtArc;
	}
	if(!p) return NotPresent;
	if(q) q -> nxtArc = p -> nxtArc;
	else a[u] = p -> nxtArc;
	delete p;
	e--;
	return Success;
}
int main(int argc, char const *argv[])
{
	LGraph<int> lg(4);
	int w = 4; lg.Insert(1, 0, w); lg.Output();
	w = 5; lg.Insert(1, 2, w); lg.Output();
	w = 3; lg.Insert(2, 3, w); lg.Output();
	w = 1; lg.Insert(3, 0, w); lg.Output();
	w = 1; lg.Insert(3, 1, w); lg.Output();
	return 0;
}

图的邻接表实现_LGraph

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原文地址：http://blog.csdn.net/gkhack/article/details/50214577