图的邻接矩阵实现

#include <iostream>
#include <string>
#define WUXIANG 0
using namespace std;
struct Graph
{
    
    
	int vertexs;	//头节点
	int edges;		//边
	char* pVertex;	//用来存放所有的顶点。
	int** ppEdge;	//用来存储所有的边。

};
//创建图对象
Graph* CreateGraph();
//释放图对象
void destroyGraph(Graph* g);
//初始化图对象
void initGraph(Graph* g);
//获取顶点的图中的下标，如果顶点没有，返回-1；
int _getIdx(Graph* g, char c);
//把图打印出来看一下。
void show(Graph* g);
int main()
{
    
    
	//创建图对象
	Graph* g = CreateGraph();
	//初始化图对象
	initGraph(g);
	//显示图
	show(g);
	//释放图对象；
	destroyGraph(g);
	system("pause");
	return 0;
}
//初始化图对象
void initGraph(Graph* g)
{
    
    
	cout << "请输入顶点的个数:\n";
	cin >> g->vertexs;
	cout << "请输入边条数：\n";
	cin >> g->edges;
	//开内存：
	g->pVertex = new char[g->vertexs + 1];//保存顶点的一维数组
	g->ppEdge = new int* [g->vertexs];//保存描述边的二维数组。
	for (int i = 0; i < g->vertexs; i++)
	{
    
    
		g->ppEdge[i] = new int[g->vertexs];
		memset(g->ppEdge[i], 0, sizeof(int) * g->vertexs);
	}
	//赋值
	cout << "请输入顶点：\n";
	cin >> g->pVertex; //自己写就可以这样，如果是给别人就老实用循环
	char buff[5] = {
    
     0 };
	int srcIdx, dstIdx;
	for (int i = 1; i <= g->edges; i++)
	{
    
    
		cout << "请输入第" << i << "条边(A->B):";
		cin >> buff;
		srcIdx = _getIdx(g, buff[0]);
		dstIdx = _getIdx(g, buff[3]);
		g->ppEdge[srcIdx][dstIdx] = 1;
		//如果是无向图，就加一行代码
#if WUXIANG 
		g->ppEdge[dstIdx][srcIdx] = 1;
#endif
	}

}
//创建图
Graph* CreateGraph()
{
    
    
	Graph* graph = new Graph;
	graph->edges = graph->vertexs = 0;
	graph->ppEdge = nullptr;
	graph->pVertex = nullptr;
	return graph;
}
void destroyGraph(Graph* g)
{
    
    
	delete[]g->ppEdge;
	delete[]g->pVertex;
}
int _getIdx(Graph* g, char c)
{
    
    
	for (int i = 0; i < g->vertexs; i++)
	{
    
    
		if (c == g->pVertex[i])
			return i;
	}
	return -1;
}
void show(Graph* g)
{
    
    
	for (int i = 0; i <= g->vertexs; i++)
	{
    
    
		for (int j = 0; j <= g->vertexs; j++)
		{
    
    
			if (i == 0 && j == 0)//左上角空置
				cout << " ";
			else if (i == 0)
			{
    
    
				cout << g->pVertex[j - 1] << " ";
			}
			else if (j == 0)
				cout << g->pVertex[i - 1] << " ";
			else
			{
    
    
				cout << g->ppEdge[i - 1][j - 1] << " ";
			}
		}
		cout << endl;
	}
}