Submission #1042886

#	Time	Username	Problem	Language	Result	Execution time	Memory
1042886		kwongweng	Longest Trip (IOI23_longesttrip)	C++17	85 / 100	10 ms	708 KiB

longesttrip

#include "longesttrip.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef pair<int, int> ii;
typedef vector<ii> vii;
typedef long double ld;
typedef vector<vector<ll>> vll;
#define FOR(i, a, b) for(int i = a; i < b; i++)
#define ROF(i, a, b) for(int i = a; i >= b; i--)
#define pb push_back
#define ms memset
#define fi first
#define se second

vi longest_trip(int N, int D)
{
    vector<vi> CC;
    FOR(i,0,N) CC.pb({i});
    while (CC.size() > 2){
        int sz = CC.size(), s0 = CC[0].size(), s1 = CC[1].size(), sn = CC[sz-1].size();
        if (are_connected({CC[sz-1][0]}, {CC[0][s0-1]})){
            FOR(i,0,sn){
                CC[0].pb(CC[sz-1][i]);
            }
            CC.pop_back(); continue;
        }
        if (are_connected({CC[sz-1][0]}, {CC[1][s1-1]})){
            FOR(i,0,sn){
                CC[1].pb(CC[sz-1][i]);
            }
            CC.pop_back(); continue;
        }
        ROF(i,s1-1,0){
            CC[0].pb(CC[1][i]);
        }
        FOR(i,1,sz-1){
            CC[i]=CC[i+1];
        }
        CC.pop_back();
    }
    int s0 = CC[0].size(), s1 = CC[1].size();
    if (are_connected(CC[0], CC[1])){
        if (are_connected({CC[0][0]}, {CC[1][0]})){
            reverse(CC[0].begin(), CC[0].end());
            FOR(i,0,s1) CC[0].pb(CC[1][i]);
            return CC[0];
        }
        if (are_connected({CC[0][0]}, {CC[1][s1-1]})){
            reverse(CC[0].begin(), CC[0].end());
            reverse(CC[1].begin(), CC[1].end());
            FOR(i,0,s1) CC[0].pb(CC[1][i]);
            return CC[0];
        }
        if (are_connected({CC[0][s0-1]}, {CC[1][0]})){
            FOR(i,0,s1) CC[0].pb(CC[1][i]);
            return CC[0];
        }
        if (are_connected({CC[0][s0-1]}, {CC[1][s1-1]})){
            reverse(CC[1].begin(), CC[1].end());
            FOR(i,0,s1) CC[0].pb(CC[1][i]);
            return CC[0];
        }
        int l = 0, r = s0;
        while (r-l>1){
            int mid = (l+r)/2;
            vi A; FOR(i,0,mid) A.pb(CC[0][i]);
            if (are_connected(A, CC[1])){
                r = mid;
            }else{
                l = mid;
            }
        }
        int a = l; l=0; r=s1;
        while (r-l>1){
            int mid = (l+r)/2;
            vi A; FOR(i,0,mid) A.pb(CC[1][i]);
            if (are_connected({CC[0][a]}, A)){
                r=mid;
            }else{
                l=mid;
            }
        }
        vi ans;
        FOR(i,a+1,a+s0+1) ans.pb(CC[0][i%s0]);
        FOR(i,l,l+s1) ans.pb(CC[1][i%s1]);
        return ans;
    }
    if (CC[0].size()>CC[1].size()) return CC[0];
    return CC[1];
}

• Subtask 0: 0 / 0
• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 25 / 25
• Subtask 4: 45 / 60