Submission #319556

#	Time	Username	Problem	Language	Result	Execution time	Memory
319556		VEGAnn	Fun Tour (APIO20_fun)	C++14	0 / 100	6 ms	5228 KiB

fun

#include "fun.h"
#include <bits/stdc++.h>
#define PB push_back
#define sz(x) ((int)x.size())
#define i2 array<int,2>
#define all(x) x.begin(),x.end()
using namespace std;
const int N = 100100;
vector<int> g[N], ans, vc[2];
int siz[N], glob, mx;
bool mrk[N];

void dfs(int v, int p, int len){
    if (mx < len){
        mx = len;
        glob = v;
    }

    for (int u : g[v]){
        if (u == p || mrk[u]) continue;

        dfs(u, v, len + 1);
    }
}

int get(int v, int tp){
    for (int it = sz(g[v]) - 1; it >= 0; it--){
        int u = g[v][it];

        if (mrk[u]) continue;

        get(u, tp);
    }

    vc[tp].PB(v);
}

vector<int> createFunTour(int n, int Q) {
//    if (n <= 500){
//        for (int i = 0; i < n; i++)
//        for (int j = i + 1; j < n; j++){
//            int now = hoursRequired(i, j);
//
//            if (now == 1){
//                g[i].PB(j);
//                g[j].PB(i);
//            }
//        }
//    } else
    {
//        if (n < 10) while (1) {}

        for (int i = 1; i < n; i++){
            int j = (i - 1) / 2;

//            g[i].PB(j);
            g[j].PB(i);
        }

        int rem = n, root = 0;

        while (rem > 0){
            vc[0].clear();
            vc[1].clear();

            if (sz(g[root]) > 0 && !mrk[g[root][0]]) get(g[root][0], 0);
            if (sz(g[root]) > 1 && !mrk[g[root][1]]) get(g[root][1], 1);

            if (sz(vc[0])){
                sort(all(vc[0]));
                reverse(all(vc[0]));
            }

            if (sz(vc[1])){
                sort(all(vc[1]));
                reverse(all(vc[1]));
            }

            for (int i = 0; i < sz(vc[1]); i++){
                ans.PB(vc[0][i]);
                ans.PB(vc[1][i]);

                mrk[vc[0][i]] = 1;
                mrk[vc[1][i]] = 1;

                rem -= 2;
            }

            if (sz(vc[0]) == sz(vc[1])){
                rem--;
                assert(rem == 0);

                ans.PB(root);

                break;
            } else {
                rem -= 2;

                ans.PB(vc[0][sz(vc[1])]);
                ans.PB(root);

                mrk[vc[0][sz(vc[1])]] = 1;
                mrk[root] = 1;
            }

            if (rem == 0) break;

            root = g[root][0];
            assert(!mrk[root]);
        }

        return ans;
    }

    ans.clear();

    mx = -1;

    dfs(0, -1, 0);

    for (int it = 0; it < n; it++){
        ans.PB(glob);
        mrk[glob] = 1;

        mx = -1;

        dfs(glob, -1, 0);
    }

    return ans;
}

Compilation message (stderr)

fun.cpp: In function 'int get(int, int)':
fun.cpp:36:1: warning: no return statement in function returning non-void [-Wreturn-type]
   36 | }
      | ^

• Subtask 1: 0 / 10
• Subtask 2: 0 / 16
• Subtask 3: 0 / 21
• Subtask 4: 0 / 19
• Subtask 5: 0 / 34