A1032 Sharing (25) 静态链表

#include<cstdio>
#include<iostream>
using namespace std;
const int maxn=1000001;
struct Node
{
	char c;
	int next;
}node[maxn];
bool hashtable[maxn]={false};
int main()
{
	int a,b,n;
	cin>>a>>b>>n;
	for (int i=0;i<n;i++)
    {
    	int t1,t2;
    	char t;
    	scanf("%d %c %d",&t1,&t,&t2);
    	node[t1].c=t1;
    	node[t1].next=t2;
    }
    int i=-1;
    for(i=a;i!=-1;)
    {
    	hashtable[i]=true;
    	i=node[i].next;
	}
	for(i=b;i!=-1;)
    {
     	if(hashtable[i]==true)
    	break;
    	i=node[i].next;
	}
	if(i==-1)
	{
		printf("-1");
	}
	else
	{
		printf("%05d",i);
	}
	
}