L2-1連結串列去重(25分)

#include<iostream>
#include<cstdio>
#include<vector>
#include<algorithm>
#include<cstring>
#include<string>
#include<map>
#include<queue>
#include<iomanip>
using namespace std;
#define STDIN freopen("in.in", "r", stdin);freopen("out.out", "w", stdout);


const
 
 int N = 1e7 + 10;

int head, ne[N],v[N];
int n;
bool st[N];
int main()
{
//     STDIN
    cin >> head >> n;
    memset(ne, -1, sizeof ne);
    for (int i = 1; i <= n; i++)
    {
        int id, val, nid;
        cin >> id >> val >> nid;
        v[id] = val;
        ne[id] 
 
= nid;
    }
    int now = head;
    // printf("%05d %d %5d\n", head, v[head], ne[head]);
    vector<pair<int, int > > vec1;
    vector<pair<int, int> > vec2;
    vec1.push_back({head, v[head]});
    st[abs(v[head])] = true;
    while (ne[now] != -1)
    {
        now = ne[now];
        
 
if (!st[abs(v[now])])
            vec1.push_back({now, v[now]}), st[abs(v[now])] = true;
        else vec2.push_back({now, v[now]});
    }
    int len = vec1.size();
    // cout << vec1.size() << endl;
    for (int i = 0; i < len; i++)
    {
        if (i != len-1)
            printf("%05d %d %05d\n", vec1[i].first, vec1[i].second, vec1[i+1].first);
        else printf("%05d %d %d\n", vec1[i].first, vec1[i].second, -1);
    }
    len = vec2.size();
    
    for(int i = 0; i < len; i++)
    {
        if (i!= len-1)
            printf("%05d %d %05d\n", vec2[i].first, vec2[i].second, vec2[i+1].first);
        else printf("%05d %d %d\n", vec2[i].first, vec2[i].second, -1);
    }
}