Submission #1030574

#	Time	Username	Problem	Language	Result	Execution time	Memory
1030574		boyliguanhan	Fun Tour (APIO20_fun)	C++17	100 / 100	145 ms	20772 KiB

fun

#include "fun.h"

#include <bits/stdc++.h>
using namespace std;
#define S(A) sort(A.begin(),A.end())
typedef vector<pair<int,int>> VP;
vector<int>ans;
#define PB push_back
void makedouble(VP a,VP b){
    S(b),S(a);
    while(a.size()||b.size()){
        ans.PB(b.back().second);
        b.pop_back();
        swap(a,b);
    }
}
VP concat(VP a,VP b){
    for(auto i:b)
        a.PB(i);
    return a;
}
void stuff(VP W[3],int a,int b,int c,int k){
    if(k==a) makedouble(W[a],concat(W[b],W[c]));
    else if(W[b+c-k].back().first>W[k].back().first)
        makedouble(W[a],concat(W[b],W[c]));
    else makedouble(concat(W[b],W[c]),W[a]);
}
vector<int> createFunTour(int N, int Q) {
    ans.clear();
    if(N==2) return{0,1};
    pair<int,int>centroid{N,0};
    for(int i=1;i<N;i++) {
        int k=attractionsBehind(0,i);
        if(k>=(N+1)/2)
            centroid=min(centroid,{k,i});
    }
    int k=centroid.second;
    vector<int>subtreez;
    VP W[3];
    for(int i=0;i<N;i++){
        if(i==k) continue;
        int C=hoursRequired(k,i);
        if(!subtreez.size()){
            subtreez.PB(i);
            W[0].PB({C,i});
        } else if(subtreez.size()==1){
            if(W[0][0].first+C-hoursRequired(W[0][0].second,i))
                W[0].PB({C,i});
            else subtreez.PB(i),W[1].PB({C,i});
        } else {
            if(W[0][0].first+C-hoursRequired(W[0][0].second,i))
                W[0].PB({C,i});
            else if(W[1][0].first+C-hoursRequired(W[1][0].second,i))
                W[1].PB({C,i});
            else W[2].PB({C,i});
        }
    }
    S(W[0]),S(W[1]),S(W[2]);
    sort(W,W+3,[](VP &a,VP &b){
        return a.size()>b.size();
    });
    if(W[2].empty()){
        makedouble(W[1],W[0]);
    } else if(W[0].size()>=W[1].size()+W[2].size()){
        makedouble(concat(W[1],W[2]), W[0]);
    } else {
        sort(W,W+3,[](VP &a,VP &b){
            return a.back()>b.back();
        });
        int prv=0;
        ans.PB(W[0].back().second);
        W[0].pop_back();
        while(1){
            if(ans.size()==119){
                cerr<<"ohaiyo\n";
            }
            int A=W[0].size(),B=W[1].size(),C=W[2].size();
            if(A+B==C){
                stuff(W,2,0,1,prv);
                break;
            } else if (A+C==B){
                stuff(W,1,2,0,prv);
                break;
            } else if (B+C==A){
                stuff(W,0,1,2,prv);
                break;
            }
            pair<int,int>s{0,0};
            for(int i=0;i<3;i++)if(i-prv)
                s=max(s,{W[i].back().first,i});
            prv=s.second;
            ans.PB(W[prv].back().second);
            W[prv].pop_back();
        }
    }
    ans.PB(k);
    return ans;
}

• Subtask 1: 10 / 10
• Subtask 2: 16 / 16
• Subtask 3: 21 / 21
• Subtask 4: 19 / 19
• Subtask 5: 34 / 34