Submission #803148

#	Time	Username	Problem	Language	Result	Execution time	Memory
803148		TB_	Village (BOI20_village)	C++17	50 / 100	71 ms	17200 KiB

Village

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

// #undef _GLIBCXX_DEBUG                // disable run-time bound checking, etc
// #pragma GCC optimize("Ofast,inline") // Ofast = O3,fast-math,allow-store-data-races,no-protect-parens
// #pragma GCC optimize ("unroll-loops")

// #pragma GCC target("bmi,bmi2,lzcnt,popcnt")                      // bit manipulation
// #pragma GCC target("movbe")                                      // byte swap
// #pragma GCC target("aes,pclmul,rdrnd")                           // encryption
// #pragma GCC target("avx,avx2,f16c,fma,sse3,ssse3,sse4.1,sse4.2") // SIMD

// #include <bits/extc++.h>
// using namespace __gnu_pbds;
// template<class T>using ordered_set = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>;
// template<class T>using ordered_multiset = tree<T, null_type, less_equal<T>, rb_tree_tag,tree_order_statistics_node_update>;

#define ll long long
#define INF (ll)1e9+7
#define fo(i, n) for(int i=0;i<((ll)n);i++)
#define deb(x) cout << #x << " = " << x << endl;
#define deb2(x, y) cout << #x << " = " << x << ", " << #y << " = " << y << endl
#define pb push_back
#define mp make_pair
#define F first
#define S second
#define LSOne(S) ((S) & (-S))
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
inline int readint(){ int v = 0; char c; while((c = getchar()) != EOF && c != ' ' && c != '\n'){ v *= 10; v += c - '0'; } return v; }
inline int readintsigned() { int v = 0; int sign = 1; char c = getchar(); if (c == '-') { sign = -1; } else { v += c - '0'; } while ((c = getchar()) != EOF && c != ' ' && c != '\n') { v *= 10; v += c - '0'; } return v * sign; }
inline string readstring() { string s; char c; while ((c = getchar()) != EOF && c != '\n' && c != ' ') { s.push_back(c); } return s; }
template <class result_t=std::chrono::milliseconds,class clock_t=std::chrono::steady_clock,class duration_t = std::chrono::milliseconds>
auto since(std::chrono::time_point<clock_t, duration_t> const& start){return std::chrono::duration_cast<result_t>(clock_t::now() - start);}
typedef pair<int, int> pii;
typedef pair<ll, ll> pl;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<pii> vpii;
typedef vector<pl> vpl;
typedef vector<vi> vvi;
typedef vector<vl> vvl;
typedef vector<vpii> vvpii;
typedef vector<vpl> vvpl;

vvl adj(100001);
int n, from, to;
int centroid = 0;
vector<pair<int, vi>> fromTree;

int dfs(int pos, int last = -1){
    int total = 1;
    for(auto v : adj[pos]){
        if(last == v) continue;
        total += dfs(v, pos);
    }
    if(total > n/2){
        centroid = pos;
        return 0;
    }
    return total;
}


void dfs2(int u, int last){
    fromTree[fromTree.size()-1].S.pb(u);
    fromTree[fromTree.size()-1].F++;
    for(auto v : adj[u]){
        if(v == last) continue;
        dfs2(v, u);
    }
}

pl dfsAns(int u, int last = -1){
    pl current = {1, 0}; // amount, travel
    for(auto v : adj[u]){
        if(v == last) continue;
        pl res = dfsAns(v, u);
        current.F += res.F;
        current.S += res.S+res.F*2LL;
    }
    return current;
}

int main() {
    // cout << fixed << setprecision(20);
    // auto start = std::chrono::steady_clock::now(); // since(start).count()
    cin.tie(0)->sync_with_stdio(0);

    cin >> n;
    fo(i, n-1){
        cin >> from >> to;
        adj[--from].pb(--to);
        adj[to].pb(from);
    }

    if(n == 2){
        cout << "2 2\n2 1\n2 1";
        exit(0);
    }

    dfs(0);
    vi hiAns(n);

    for(auto v : adj[centroid]){
        fromTree.pb({0, {}});
        dfs2(v, centroid);
    }
    sort(rall(fromTree));
    int last = centroid;
    int currentSum = 0;
    
    vl villages;
    for(auto subtree : fromTree){
        for(auto v : subtree.S) {
            villages.pb(v);
        }
    }
    villages.pb(centroid);

    
    fo(i, n){
        // deb(i/2+((i%2)^(n%2)?n/2:0));
        int current = villages[i/2+((i%2)^(n%2)?n/2:0)];
        hiAns[current] = last+1;
        last = current;
    }
    cout << "0 " << dfsAns(centroid).S << "\n"; 
    fo(i, n) cout << hiAns[i] << " ";
    cout << "\n";
    fo(i, n) cout << hiAns[i] << " ";
    



    return 0;
}

Compilation message (stderr)

Village.cpp: In function 'int main()':
Village.cpp:111:9: warning: unused variable 'currentSum' [-Wunused-variable]
  111 |     int currentSum = 0;
      |         ^~~~~~~~~~

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