//用鄰接表表示圖
#include <stdio.h>
#include <stdlib.h>

#define DataType char
#define MaxVertexNum 20
#define Vertex int
#define WeightType int
typedef struct GNode *PtrToGNode;
struct  GNode
{
	int Nv;			//頂點數
	int Ne;			//邊數
	AdjList G;		//鄰接表
};

struct ENode{
	Vertex v1, v2;
	int weight;
};

typedef struct ENode* Edge;

typedef PtrToGNode LGraph;	//以鄰接表方式儲存的圖型別

typedef struct Vnode {
	PtrToAdjVNode FirstEdge;
	DataType Data; //存頂點的資料
}AdjList[MaxVertexNum];

typedef struct AdjVNode *PtrToAdjVNode;
struct AdjVNode {
	Vertex AdjV;			//鄰接點下標
	WeightType Weight;		//邊的權重
	PtrToAdjVNode Next;		
};

//初始化一個有VertexNum個頂點但沒有邊的圖

LGraph CreateGraph(int VertexNum)
{
	Vertex v;
	LGraph Graph;
	Graph = (LGraph)malloc(sizeof(struct GNode));
	Graph->Nv = VertexNum;
	Graph->Ne = 0;

	for (v = 0; v < Graph->Nv; v++)
		Graph->G[v].FirstEdge = NULL;

	return Graph;
}

void InsertEdged(LGraph Graph, Edge E)
{
	PtrToAdjVNode NewNode;
	NewNode = (PtrToAdjVNode)malloc(sizeof(struct AdjVNode));
	NewNode->AdjV = E->v2;
	NewNode->Weight = E->weight;

	//將v2插入v1的表頭
	NewNode->Next = Graph->G[E->v1].FirstEdge;
	Graph->G[E->v1].FirstEdge = NewNode;

	//若是無向圖，還要插入邊<v2, v1>
	//為v1建立新的鄰接點
	NewNode = (PtrToAdjVNode)malloc(sizeof(struct AdjVNode));
	NewNode->AdjV = E->v1;
	NewNode->Weight = E->weight;
	//將v1插入v2的表頭
	NewNode->Next = Graph->G[E->v2].FirstEdge;
	Graph->G[E->v2].FirstEdge = NewNode;
}