PAT 1032

#include<cstdio>#include<cstring>#include<algorithm>#include<iostream>#include<queue>using namespace std;const int maxn=100010;struct Node{char data;int next;bool flag;}node[maxn];int main(){int s1,s2,n;scanf("%d%d%d",&s1,&s2,&n);int add1,next;char data;int i;for(i=0;i<maxn;i++){node[i].flag=false;}for(i=0;i<n;i++){scanf("%d %c %d",&add1,&data,&next);node[add1].data=data;node[add1].next=next;}for(i=s1;i!=-1;i=node[i].next){node[i].flag=true;}for(i=s2;i!=-1;i=node[i].next){if(node[i].flag==true){printf("%05d",i);//注意输出的格式问题system("pause");return 0;}}printf("-1");system("pause");return 0;}