学步园

#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <string>

using namespace std;

struct Node
{
	char data;
	int next;
}node[100005];

int main()
{
	int head1, head2, n;
	cin >> head1 >> head2 >> n;
	if (head1 == -1 || head2 == -1) // 这个1分测试点太贱了，快把人搞崩溃
	{
		printf("-1\n");
		return 0;
	}
	int cur_addr;
	char data;
	int next;
	for (int i = 0; i < n; i++)
	{
		scanf("%d %c %d", &cur_addr, &data, &next);
	//	cin >> cur_addr >> data >> next;
		node[cur_addr].data = data;
		node[cur_addr].next = next;
	}
	int p1 = head1, p2 = head2;
	int len1 = 0, len2 = 0;
	while (p1 != -1)
	{
		len1++;
		p1 = node[p1].next;
	}
	while (p2 != -1)
	{
		len2++;
		p2 = node[p2].next;
	}
	p1 = head1, p2 = head2;
	int diff;
	if (len1 > len2)
	{
		diff = len1 - len2;
		while (diff--)
			p1 = node[p1].next;
	}
	else if (len1 < len2)
	{
		diff = len2 - len1;
		while (diff--)
			p2 = node[p2].next;
	}

	if (p1 == p2)
		printf("%05d\n", p1);
	else
	{
		int next1 = node[p1].next;
		int next2 = node[p2].next;
		while (next1 != next2)
		{
			p1 = next1;
			next1 = node[p1].next;
			p2 = next2;
			next2 = node[p2].next;
		}
		if (next1 == -1)
		{
			if (p1 == p2)
				printf("%05d\n", p1);
			else
				printf("-1\n");
		}
		else
			printf("%05d\n", next1);
	}
	return 0;
}