Submission #1101947

#	Time	Username	Problem	Language	Result	Execution time	Memory
1101947		crafticat	Village (BOI20_village)	C++17	0 / 100	1 ms	336 KiB

Village

#include "bits/stdc++.h"

using namespace std;
template<typename T>
using V = vector<T>;
using vi = V<int>;
using vvi = V<vi>;
using pi = pair<int,int>;
using vpi = V<pi>;

#define F0R(i, n) for(int i = 0; i < n;i++)
#define FOR(i,a, n) for(int i = a; i < n;i++)
#define pb push_back

V<bool> state;
int sum;
vi to;
vvi g;

void dfs(int x, int p) {
    vi child;
    
    for (auto v : g[x]) {
        if (p == v) continue;
        dfs(v, x);
        if (state[v]) continue;
        child.pb(v);
    }

    for (int i = 0; i < child.size() / 2; ++i) {
        to[child[i]] = child[i + 1];
        to[child[i + 1]] = child[i];
        sum += 2;
    }
    if (child.size() % 2 == 1) {
        to[child[child.size() - 1]] = x;
        to[x] = child[child.size() - 1];
        sum += 2;
        state[x] = true;
    }

    if (p == -1 && !state[x]) {
        to[x] = g[x][0];
        to[to[g[x][0]]] = x;
        sum += 2;
    }
}

int main() {
    ios_base::sync_with_stdio(false); cin.tie(nullptr);

    int n; cin >> n;
    g.resize(n + 1);
    state.resize(n + 1);
    to.resize(n + 1);

    F0R(i, n - 1) {
        int a, b; cin >> a >> b;
        g[a].pb(b);
        g[b].pb(a);
    }

    dfs(1,-1);

    cout << sum << " 6\n";
    FOR(i, 1, n + 1)
        cout << to[i] << " ";
    cout << "\n";
    FOR(i, 1, n + 1)
        cout << to[i] << " ";

    return 0;
}

Compilation message (stderr)

Village.cpp: In function 'void dfs(int, int)':
Village.cpp:30:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   30 |     for (int i = 0; i < child.size() / 2; ++i) {
      |                     ~~^~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 12
• Subtask 2: 0 / 38
• Subtask 3: 0 / 50