C++ 代码

#include<bits/stdc++.h>
using namespace std;
const int N = 1e5+10;
struct node{
    char data;
    int next;
    bool flag;
}node[N];
int main(){
    int s1,s2,n;
    cin>>s1>>s2>>n;
    char data;
    int a1,a2;
    for(int i = 0;i<n;i++){
        cin>>a1>>data>>a2;
        node[a1].data=data;
        node[a1].next=a2;
        node[a1].flag = false;
    }
    for(int i = s1;i!=-1;i=node[i].next){
        node[i].flag = true;
    }
    for(int i = s2;i!=-1;i=node[i].next){
        if(node[i].flag == true) {
            printf("%05d",i);
            return 0;
        }
    }
    cout<<"-1";
    return 0;
}