const int maxpoint = 505;
const int maxroads = 10005;
#define MAXN maxpoint
#define MAXM maxroads
//图的定义:临接链表的数组实现
int aterm[MAXN];
int bterm[MAXM],Next[MAXM];
int N,M,roads;
void init() {
	roads = 0;
	for (int i = 1; i <= N; ++i) aterm[i] = 0;
}
void Insertroad(int a,int b) {
	Next[++roads] = aterm[a];
	bterm[roads] = b;
	aterm[a] = roads;
}
遍历由a可直接到达的点的方法：
for (int p = aterm[a]; p; p = Next[p]) {do something with bterm[p];}