Submission #823312

#	Time	Username	Problem	Language	Result	Execution time	Memory
823312		LucaIlie	Construction of Highway (JOI18_construction)	C++17	100 / 100	1068 ms	41976 KiB

construction

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define debug(x) cerr << #x << " " << x << "\n"
#define debugs(x) cerr << #x << " " << x << " "
#pragma GCC optimize("Ofast,unroll-loops")
 
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef pair <ll, ll> pii;
typedef pair <long double, pii> muchie;
typedef tree <ll, null_type, less_equal <ll>, rb_tree_tag, tree_order_statistics_node_update> OST;
 
const ll NMAX = 100001;
const ll INF = (1LL << 60);
const ll HALF = (1LL << 59);
const ll MOD = 1000000007;
const ll BLOCK = 318;
const ll base = 31;
const ll nr_of_bits = 21;
 
ll n;
ll dp[NMAX][nr_of_bits + 1];
 
class All {
public:
    ll all[NMAX * 4];
    ll lazy[NMAX * 4];
    void propaga(ll node, ll st, ll dr) {
        if(!lazy[node])
            return;
        if(st != dr) {
            lazy[node * 2] = lazy[node];
            lazy[node * 2 + 1] = lazy[node];
        }
        all[node] = lazy[node];
        lazy[node] = 0;
    }
    void update(ll node, ll st, ll dr, ll a, ll b, ll val) {
        propaga(node, st, dr);
        if(a <= st && dr <= b) {
            lazy[node] = val;
                  propaga(node, st, dr);
 
            return;
        }
        ll mid = (st + dr) / 2;
        propaga(node * 2, st, mid);
        propaga(node * 2 + 1, mid + 1, dr);
        if(a <= mid) {
            update(node * 2, st, mid, a, b, val);
        }
        if(b > mid) {
            update(node * 2 + 1, mid + 1, dr, a, b, val);
        }
        propaga(node * 2, st, mid);
        propaga(node * 2 + 1, mid + 1, dr);
        all[node] = max(all[node * 2], all[node * 2 + 1]);
    }
    ll maxim(ll node, ll st, ll dr, ll a, ll b) {
        propaga(node, st, dr);
        if(a <= st && dr <= b) {
            return all[node];
        }
        ll mid = (st + dr) / 2;
        ll sol = 0;
        propaga(node * 2, st, mid);
        propaga(node * 2 + 1, mid + 1, dr);
        if(a <= mid) {
            sol = max(sol, maxim(node * 2, st, mid, a, b));
        }
        if(b > mid) {
            sol = max(sol, maxim(node * 2 + 1, mid + 1, dr, a, b));
        }
        return sol;
    }
} st;
 
ll poz[NMAX];
ll stamp;
ll sz[NMAX];
ll heavy[NMAX];
ll a[NMAX];
vector <ll> v[NMAX];
 
void getsize(ll node, ll p) {
    sz[node] = 1;
    for(auto x : v[node]) {
        if(x == p)
            continue;
        getsize(x, node);
        if(heavy[node] == 0 || sz[x] > sz[heavy[node]])
            heavy[node] = x;
        sz[node] += sz[x];
    }
}
 
ll capat[NMAX];
 
void DFS(ll node, ll p, ll sf) {
    dp[node][0] = p;
    capat[node] = sf;
    poz[node] = ++stamp;
    a[stamp] = node;
    if(heavy[node])
    DFS(heavy[node], node, sf);
    for(auto x : v[node]) {
        if(x == p || x == heavy[node])
            continue;
        DFS(x, node, x);
    }
}
 
pii edges[NMAX];
ll c[NMAX];
 
void baga(ll node, ll col){
    while(node != 0){
        st.update(1, 1, n, poz[capat[node]], poz[node], col);
        node = dp[capat[node]][0];
    }
}
 
struct ura{
    ll first, second, third;
};
 
ll sol;
ll aib[NMAX];
 
ll nn;
ura nr[NMAX];
ll cv[NMAX];
 
void update(ll x, ll val){
    for(ll i = x; i <= nn; i+=i&(-i))
        aib[i] += val;
}
 
ll query(ll x){
    ll s = 0;
    for(ll i = x; i > 0; i-=i&(-i)){
        s += aib[i];
    }
    return s;
}
 
bool cmp(ura a, ura b){
    return a.first < b.first;
}
 
ll cc[NMAX];
 
void calc(){
    ll i;
    for(i = 0; i <= nn; i++)
        aib[i] = 0, cv[i] = 0, cc[i] = 0;
    sort(nr + 1, nr + nn + 1, cmp);
    ll cnt = 0;
    for(i = 1; i <= nn; i++){
        if(i == 1 || nr[i].first != nr[i - 1].first){
            cnt++;
        }
        cv[nr[i].second] = cnt;
        cc[nr[i].second] = nr[i].third;
    }
    for(i = 1; i <= nn; i++){
        sol +=  query(cv[i] - 1) * cc[i];
        update(cv[i], cc[i]);
    }
}
 
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    ll i, j;
    cin >> n;
    for(i = 1; i <= n; i++) {
        cin >> c[i];
    }
    for(i = 1; i < n; i++) {
        ll x, y;
        cin >> x >> y;
        edges[i] = {x, y};
        v[x].push_back(y);
        v[y].push_back(x);
    }
    getsize(1, 0);
    DFS(1, 0, 1);
 
    for(j = 1; j <= nr_of_bits; j++)
        for(i = 1; i <= n; i++)
            dp[i][j] = dp[dp[i][j - 1]][j - 1];
 
    st.update(1, 1, n, poz[1], poz[1], 1);
    for(i = 1; i < n; i++) {
        ll x = edges[i].first;
        ll y = edges[i].second;
        ll node = y;
        sol = 0;
        nn = 0;
        while(node != 1){
            ll dist = 1;
            node = dp[node][0];
            ll col = st.maxim(1, 1, n, poz[node], poz[node]);
            ll pas = nr_of_bits;
            while(pas >= 0){
                ll nxt = dp[node][pas];
                if(nxt != 0 && st.maxim(1, 1, n, poz[nxt], poz[nxt]) == col){
                    node = nxt;
                    dist += (1 << pas);
                }
                pas--;
            }
            nr[++nn] = {c[col], nn, dist};
        }
        calc();
        baga(y, y);
        cout << sol << "\n";
    }
    return 0;
}

Compilation message (stderr)

construction.cpp: In function 'int main()':
construction.cpp:200:12: warning: unused variable 'x' [-Wunused-variable]
  200 |         ll x = edges[i].first;
      |            ^

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