图的邻接矩阵表示及其建立（无向图）
#include <stdio.h>
#include <stdlib.h>
typedef char VertexType; //顶点类型应由用户定义
typedef int EdgeType; //边上的权值类型应由用户定义
#define MAXVEX 100 //最大顶点数，应由用户定义
#define INFINITY 65535 //用65535来代表无穷大
#define DEBUG
typedef struct
{
VertexType vexs[MAXVEX]; //顶点表
EdgeType arc[MAXVEX][MAXVEX]; //邻接矩阵，可看作边
int numVertexes, numEdges; //图中当前的顶点数和边数
}Graph;
//定位
int locates(Graph *g, char ch)
{
int i = 0;
for(i = 0; i < g->numVertexes; i++)
{
if(g->vexs[i] == ch)
{
break;
}
}
if(i >= g->numVertexes)
{
return -1;
}
return i;
}
//建立一个无向网图的邻接矩阵表示
void CreateGraph(Graph *g)
{
int i, j, k, w;
printf("输入顶点数和边数:\n");
scanf("%d %d", &(g->numVertexes), &(g->numEdges));
#ifdef DEBUG
printf("%d %d\n", g->numVertexes, g->numEdges);
#endif
for(i = 0; i < g->numVertexes; i++)
{
g->vexs[i] = getchar();
while(g->vexs[i] == '\n')
{
g->vexs[i] = getchar();
}
}
#ifdef DEBUG
for(i = 0; i < g->numVertexes; i++)
{
printf("%c ", g->vexs[i]);
}
printf("\n");
#endif
for(i = 0; i < g->numEdges; i++)
{
for(j = 0; j < g->numEdges; j++)
{
g->arc[i][j] = INFINITY; //邻接矩阵初始化
}
}
for(k = 0; k < g->numEdges; k++)
{
char p, q;
printf("输入边(vi,vj)上的顶点i，顶点j和权值:\n");
p = getchar();
while(p == '\n')
{
p = getchar();
}
q = getchar();
while(q == '\n')
{
q = getchar();
}
scanf("%d", &w);
int m = -1;
int n = -1;
m = locates(g, p);
n = locates(g, q);
if(n == -1 || m == -1)
{
fprintf(stderr, "there is no this vertex.\n");
return;
}
//getchar();
g->arc[m][n] = w;
g->arc[n][m] = g->arc[m][n]; //因为是无向图，矩阵对称
}
}
//打印图
void printGraph(Graph g)
{
int i, j;
for(i = 0; i < g.numVertexes; i++)
{
for(j = 0; j < g.numVertexes; j++)
{
printf("%d ", g.arc[i][j]);
}
printf("\n");
}
}
int main(int argc, char **argv)
{
Graph g;
//邻接矩阵创建图
CreateGraph(&g);
printGraph(g);
return 0;
}