//用鄰接矩陣表示圖
#include <stdio.h>
#include <stdlib.h>
#define MaxVertexNum 20

typedef int WeightType;
typedef char DataType;
typedef struct GNode *PtrToGNode;
typedef PtrToGNode MGraph;		//以鄰接矩陣儲存的圖型別

struct GNode {
	int Nv;		//頂點數
	int Ne;		//邊數
	WeightType G[MaxVertexNum][MaxVertexNum];
	DataType Data[MaxVertexNum];	//存頂點的資料
};



//初始化一個有VertexNUm個頂點但沒有邊的圖
typedef int Vertex;	//用頂點下標表示頂點，為整型
MGraph CreateGraph(int VertexNum)
{
	Vertex v, w;
	struct GNode* Graph;
	Graph = (MGraph)malloc(sizeof(struct GNode));
	Graph ->Nv = MaxVertexNum;
	Graph ->Ne = 0;

	//這裡的預設編號從0開始，到（Graph->Nv - 1)
	for (v = 0; v < Graph->Nv; v++)
	for (w = 0; w < Graph->Ne; w++)
		Graph->G[v][w] = 0;

	return Graph;
}

//向MGraph中插入邊
typedef struct ENode *PtrToENode;
struct ENode {
	Vertex v1, v2;		//有向邊<v2, v1>
	WeightType Weight;	//權重
};
typedef PtrToENode Edge;

void InsertEdge(MGraph Graph, Edge E)
{
	//插入邊<v1, v2>
	Graph->G[E -> v1][E->v2] = E->Weight;

	//插入邊<v2, v1>
	Graph->G[E->v2][E->v1] = E->Weight;
}

//完整地建立一個MGraph
MGraph BuildGraph()
{
	MGraph Graph;
	Edge E;
	Vertex V;
	int Nv, i;
	scanf_s("%d", &Nv);
	Graph = CreateGraph(Nv);
	scanf_s("%d", &(Graph->Ne));
	if (Graph->Ne != 0)
	{
		E = (Edge)malloc(sizeof(struct ENode));
		for (i = 0; i < Graph->Ne; i++)
			scanf_s("%d %d %d", &E->v1, &E->v2, &E->Weight);
		InsertEdge(Graph, E);
	}

	//
	for (V = 0; V < Graph->Nv; V++)
		scanf_s(" %c", Graph->Data[V]);

	return Graph;
}
 


int main()
{


	return 0;
}
 

簡化版

//用鄰接矩陣表示圖
#include <stdio.h>
#include <stdlib.h>

#define MaxN 20
int G[MaxN][MaxN], Nv, Ne;
void BuildGraph()
{
	int i , j, v1, v2, w;
	scanf("%d", &Nv);

	for (i = 0; i < Nv; i++)
	for (j = 0; j < Nv; j++)
		G[i][j] = 0;
	scanf_s("%d", &Ne);
	for (i = 0; i < Ne; i++)
	{
		scanf_s("%d %d %d", &v1, &v2, &w);
		
		G[v1][v2] = w;		//InsertEdge
		G[v2][v1] = w;
	}
}