Submission #1129026

#	Time	Username	Problem	Language	Result	Execution time	Memory
1129026		ljtunas	Construction of Highway (JOI18_construction)	C++20	100 / 100	328 ms	18768 KiB

construction

// author : anhtun_hi , nqg
// 25-26.12.2024

#include <bits/stdc++.h>
#define fi first
#define se second
#define all(x) x.begin(), x.end()
#define reset(h, v)    memset(h, v, sizeof h)
#define Forv(i, a)     for(auto& i : a)
#define For(i, a, b)   for(int i = a; i <= b; ++i)
#define Ford(i, a, b)  for(int i = a; i >= b; --i)
#define c_bit(i)     __builtin_popcountll(i)
#define Bit(mask, i)    ((mask >> i) & 1LL)
#define onbit(mask, i)  ((mask) bitor (1LL << i))
#define offbit(mask, i) ((mask) &~ (1LL << i))
#define Log2(x) (63 - __builtin_clzll(x))
#define TIME (1.0 * clock() / CLOCKS_PER_SEC)
using namespace std;

using ll = long long;
using ii = pair<ll, ll>;
using db = long double;
using ull = unsigned long long;

namespace std {
    template <typename T, int D>
    struct _vector : public vector <_vector <T, D - 1>> {
        static_assert(D >= 1, "Dimension must be positive!");
        template <typename... Args>
        _vector(int n = 0, Args... args) : vector <_vector <T, D - 1>> (n, _vector <T, D - 1> (args...)) {}
    };
    template <typename T> struct _vector <T, 1> : public vector <T> {
        _vector(int n = 0, const T& val = T()) : vector <T> (n, val) {}
    };
    template <class A, class B> bool minimize(A &a, B b){return a > b ? a = b, true : false;}
    template <class A, class B> bool maximize(A &a, B b){return a < b ? a = b, true : false;}
}
const int dx[] = {0, 0, +1, -1}, dy[] = {-1, +1, 0, 0}, LOG = 20, base = 311, inf = 1e9 + 5;
const int MAXN = 1e5 + 5;
const  ll  mod = 1e9 + 7;
const  ll   oo = 1e18;

//#define int long long

int n, c[MAXN], p[MAXN];
vector<int> g[MAXN];

struct Edge{
    int u, v;
} E[MAXN];

int sz[MAXN];
void dfs(int u, int par){
    sz[u] = 1; p[u] = par;
    Forv(v, g[u]) if(v ^ par){
        dfs(v, u);
        sz[u] += sz[v];
    }
}

int head[MAXN], in[MAXN], en[MAXN];
vector<int> List;
void build_hld(int u, int par)
{
   static int timedfs = 0;
   in[u] = ++timedfs;
   List.push_back(u);
   if(g[u].size() == 1){
      for(int v : List) head[v] = List[0]; List.clear();
   }
   for(int v : g[u])if(v != par) build_hld(v, u);
}
void init_hld(){
    For(i, 1, n) sort(all(g[i]), [&](int u, int v){
      return sz[u] > sz[v];
    });
}

ll bit[MAXN];

void upd(int u, ll val){
    while(u <= 1e5) bit[u] += val, u += u &- u;
}
ll get(int u){
    ll ans = 0;
    while(u) ans += bit[u], u -= u &- u;
    return ans;
}

int st[MAXN << 2], lazy[MAXN << 2];
ll ANS = 0;
vector<ii> rem;

void down(int id, int l, int r){
    if (lazy[id] == 0) return;
    For(i, id * 2, id * 2 + 1) lazy[i] = lazy[id], st[i] = lazy[id];
    lazy[id] = 0;
}

void update(int u, int v, int val, int id = 1, int l = 1, int r = n){
    if (v < l || r < u) return;
    if (l == r){
        if (st[id]) {
            ANS += get(st[id] - 1);
            upd(st[id], 1);
            rem.push_back({st[id], 1});
        }
        st[id] = val, lazy[id] = val;
        return;
    } else if (u <= l && r <= v && st[id]){
        ANS += get(st[id] - 1) * (r - l + 1);
        upd(st[id], r - l + 1);
        rem.push_back({st[id], r - l + 1});
        st[id] = val, lazy[id] = val;
        return;
    }
    down(id, l, r);
    int mid = l + r >> 1;
    update(u, v, val, id << 1 | 1, mid + 1, r);
    update(u, v, val, id << 1, l, mid);
    st[id] = (st[id << 1] == st[id << 1 | 1]) * st[id << 1];
}

void Solve() {
    cin >> n;
    vector<int> compress;
    For(i, 1, n) cin >> c[i], compress.push_back(c[i]);
    sort(all(compress)), compress.resize(unique(all(compress)) - compress.begin());
    For(i, 1, n) c[i] = lower_bound(all(compress), c[i]) - compress.begin() + 1;
    For(i, 1, n - 1){
        cin >> E[i].u >> E[i].v;
        p[E[i].v] = E[i].u;
        g[E[i].u].push_back(E[i].v);
        g[E[i].v].push_back(E[i].u);
    }

    dfs(1, 0);
    init_hld();
    build_hld(1, 0);

    update(1, 1, c[1]);

    For(i, 1, n - 1){
        int u = E[i].u;
        int v = E[i].v;
        ANS = 0, rem.clear();
        u = v;
        while (head[u] != head[1]){
            update(in[head[u]], in[u], c[v]);
            u = p[head[u]];
        }

        update(1, in[u], c[v]);
        Forv(tmp, rem) upd(tmp.fi, -tmp.se);
        cout << ANS << '\n';
    }

}

signed main() {
    cin.tie(0) -> sync_with_stdio(0);
    if(fopen("JOI18_construction.inp", "r")) {
        freopen("JOI18_construction.inp", "r", stdin);
        freopen("JOI18_construction.out", "w", stdout);
    }

    int t = 1;
//    cin >> t;
    while(t --) Solve();
    return 0;
}

Compilation message (stderr)

construction.cpp: In function 'int main()':
construction.cpp:163:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  163 |         freopen("JOI18_construction.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
construction.cpp:164:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  164 |         freopen("JOI18_construction.out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 9 / 9
• Subtask 3: 84 / 84