2019湖南省赛 K 双向链表练习题（list）

https://ac.nowcoder.com/acm/contest/1099/K

这题大概只要会list就会做吧。。。我是真的dd

#define bug(x) cout<<#x<<" is "<<x<<endl
#define IO std::ios::sync_with_stdio(0)
#include <bits/stdc++.h>
#define iter ::iterator
#define pa pair<int,ll>
#define pp pair<int,pa>
using namespace  std;
#define ll long long
#define mk make_pair
#define pb push_back
#define se second
#define fi first
#define ls o<<1
#define rs o<<1|1
ll mod=998244353;
const int N=2e5+5;
list<int>L[N],D[N];
int n,m;
int main(){
    while(~scanf("%d%d",&n,&m)){
        for(int i=1;i<=n;i++){
            L[i].clear();
            D[i].clear();
            L[i].pb(i);
            D[i].pb(i);
        }
        vector<int>ans;
        while(m--){
            int x,y;
            scanf("%d%d",&x,&y);
            L[x].splice(L[x].end(),L[y]);
            D[y].splice(D[y].end(),D[x]);
            swap(L[x],D[y]);
            swap(D[x],D[y]);
            L[y].clear();
            D[y].clear();
        }
        for(auto tmp:L[1]){
            ans.pb(tmp);
        }
        int h=ans.size();
        printf("%d ",h);
        for(int i=0;i<h;i++){
            printf("%d ",ans[i]);
        }
        printf("
");
    }
}