Submission #940731

#	Time	Username	Problem	Language	Result	Execution time	Memory
940731		Pring	Village (BOI20_village)	C++17	50 / 100	135 ms	25216 KiB

Village

#include <bits/stdc++.h>
using namespace std;

#ifdef MIKU
const string dbmc = "\033[1;38;2;57;197;187m", dbrs = "\033[0m";
#define debug(x...) cout << dbmc << '[' << #x << "] : ", dout(x)
void dout() { cout << dbrs << endl; }
template <typename T, typename ...U>
void dout(T t, U ...u) { cout << t << (sizeof...(u) ? ", " : ""); dout(u...); }
#else
#define debug(...) 39
#endif

#define int long long
#define fs first
#define sc second
#define mp make_pair
#define FOR(i, j, k) for (int i = j, Z = k; i < Z; i++)
typedef pair<int, int> pii;

const int MXN = 100005;
int n;
vector<int> edge[MXN];

namespace NSA {
    int ans, va[MXN], sz[MXN];
    int bind[MXN];

    void DFS(int id, int par) {
        sz[id] = 1;
        vector<int> odd;
        for (auto &i : edge[id]) {
            if (i == par) continue;
            DFS(i, id);
            sz[id] += sz[i];
            if (sz[i] & 1) odd.push_back(i);
        }
        odd.push_back(id);
        for (int i = 1; i < odd.size(); i += 2) {
            bind[odd[i - 1]] = odd[i];
            bind[odd[i]] = odd[i - 1];
            ans += (odd[i] == id ? 2 : 4);
        }
    }

    void DO() {
        int lf = [&]() -> int {
            FOR(i, 1, n + 1) if (edge[i].size() == 1) return i;
            return 0;
        }();
        int rt = edge[lf][0];
        if (n % 2 == 0) {
            DFS(rt, 0);
        } else {
            edge[n + 1].push_back(rt);
            edge[rt].push_back(n + 1);
            DFS(n + 1, 0);
            ans -= 2;
            bind[rt] = rt;
            swap(bind[rt], bind[lf]);
        }
        copy(bind + 1, bind + n + 1, va + 1);
    }
}

namespace NSB {
    int ans, va[MXN];
    int sz[MXN];
    bitset<MXN> ban;

    int GET_ANS(int id, int par) {
        sz[id] = 1;
        int ans = 0;
        for (auto &i : edge[id]) {
            if (i == par) continue;
            ans += GET_ANS(i, id);
            sz[id] += sz[i];
        }
        return (ans + min(n - sz[id], sz[id]) * 2);
    }

    void GET_SZ(int id, int par) {
        sz[id] = 1;
        for (auto &i : edge[id]) {
            if (i == par) continue;
            if (ban[i]) continue;
            GET_SZ(i, id);
            sz[id] += sz[i];
        }
    }

    int GET_CD(int id, int par, int N) {
        for (auto &i : edge[id]) {
            if (i == par) continue;
            if (ban[i]) continue;
            if (sz[i] > N / 2) return GET_CD(i, id, N);
        }
        return id;
    }

    vector<int> CD(int id) {
        GET_SZ(id, 0);
        if (sz[id] == 1) return vector<int>(1, id);
        vector<int> w(sz[id]), wid;
        for (int i = 0; i < sz[id]; i += 2) wid.push_back(i);
        for (int i = 1; i < sz[id]; i += 2) wid.push_back(i);
        int cd = GET_CD(id, 0, sz[id]);
        vector<vector<int>> v;
        ban[cd] = true;
        for (auto &i : edge[cd]) {
            if (ban[i]) continue;
            v.push_back(CD(i));
        }
        sort(v.begin(), v.end(), [&](vector<int> &a, vector<int> &b) -> bool {
            return a.size() > b.size();
        });
        v.back().push_back(cd);
        int C = 0;
        for (auto &i : v) for (auto &j : i) w[wid[C++]] = j;
        return w;
    }

    void DO() {
        ans = GET_ANS(1, 0);
        vector<int> v = CD(1);
        v.push_back(v[0]);
        FOR(i, 1, n + 1) va[v[i - 1]] = v[i];
    }
}

void miku() {
    int x, y;
    cin >> n;
    FOR(i, 1, n) {
        cin >> x >> y;
        edge[x].push_back(y);
        edge[y].push_back(x);
    }
    NSB::DO();
    NSA::DO();
    cout << NSA::ans << ' ' << NSB::ans << '\n';
    FOR(i, 1, n + 1) cout << NSA::va[i] << ' ';
    cout << '\n';
    FOR(i, 1, n + 1) cout << NSB::va[i] << ' ';
    cout << '\n';
}

int32_t main() {
    cin.tie(0) -> sync_with_stdio(false);
    cin.exceptions(iostream::failbit);
    miku();
    return 0;
}

Compilation message (stderr)

Village.cpp: In function 'void NSA::DFS(long long int, long long int)':
Village.cpp:39:27: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   39 |         for (int i = 1; i < odd.size(); i += 2) {
      |                         ~~^~~~~~~~~~~~

• Subtask 1: 6 / 12
• Subtask 2: 19 / 38
• Subtask 3: 25 / 50