Submission #1279105

#	Time	Username	Problem	Language	Result	Execution time	Memory
1279105		dosts	Construction of Highway (JOI18_construction)	C++20	100 / 100	193 ms	22392 KiB

construction

#include <bits/stdc++.h>
#define int long long
#define pii pair<int,int>
#define vi vector<int>
#define ff first
#define ss second
#define sp << " " <<
#define all(x) x.begin(),x.end()
#define big(x) ((int)(x.size()))
using namespace std;
const int MOD = 1e9+7, LIM = 1e6+1, inf = 2e9;

const int N = 1e5+1;
vi edges[N],sub(N),tp(N),par(N),dep(N);

struct FT {
    vi bit;
    int n;
    vector<pii> upds;
    FT(int nn) {
        n = nn;
        bit.assign(n + 1, 0);
    }
    void put(int p, int v,int r = 0) {
        if (!r) upds.push_back({p,v});
        for (int i = p; i <= n; i += i & -i) bit[i] += v;
    }
    int get(int p) {
        int ans = 0;
        for (int i = p; i > 0; i -= i & -i) ans += bit[i];
        return ans;
    }
    int get(int l, int r) {
        return get(r) - get(l - 1);
    }
    void reset() {
        for (auto it : upds) put(it.ff,-it.ss,1);
        upds.clear();
    }
};

void dfs(int node,int p) {
    if (node == p) dep[node] = 0;
    else dep[node] = dep[p]+1;
    par[node] = p;
    sub[node] =1 ;
    for (auto it : edges[node]) {
        if (it == p) continue;
        dfs(it,node);
        sub[node]+=sub[it];
    }
}

void hld(int node,int t) {
    tp[node] = t;
    int hvy = -1;
    for (auto it : edges[node]) {
        if (hvy == -1 || sub[it] > sub[hvy]) hvy = it;
    }
    if (hvy == -1) return;
    hld(hvy,t);
    for (auto it : edges[node]) if (it != hvy) hld(it,it);
}

vector<pii> stuf[N];

void solve() {
    int n;
    cin >> n;
    vi c(n+1);
    vi v;
    for (int i=1;i<=n;i++) {
        cin >> c[i];
        v.push_back(c[i]);
    }
    sort(all(v));
    v.erase(unique(all(v)),v.end());
    for (int i=1;i<=n;i++) c[i] = upper_bound(all(v),c[i])-v.begin();
    vector<pii> edg;
    for (int i=1;i<n;i++) {
        int a,b;
        cin >> a >> b;
        edg.push_back({a,b});
        edges[a].push_back(b);
    }
    dfs(1,1);
    hld(1,1);
    vector<pii> chns;
    FT ft(n);
    auto qry = [&](int node,int v) -> int {
        int cur = node;
        int ans = 0;
        ft.reset();
        chns.clear();
        while (1) {
            int chain = tp[cur];
            chns.push_back({chain,cur});
            if (chain == 1) break;
            cur = par[chain];
        }
        reverse(all(chns));
        for (auto& [chain,curr] : chns) {
            for (int i = big(stuf[chain])-1;i>=0;i--) {
                int dp = dep[stuf[chain][i].ff];
                int amt = (i == big(stuf[chain])-1)?(dp-dep[chain]+1):
                                                   (dp-dep[stuf[chain][i+1].ff]);
                amt-=max(0ll,dp-dep[curr]);
                amt = max(amt,0ll);
                if (!amt) break;
                ans+=amt*ft.get(stuf[chain][i].ss+1,n);
                ft.put(stuf[chain][i].ss,amt);
            }
        }
        return ans;
    };

    auto upd = [&](int node,int v) -> void {
        int cur = node;
        while (1) {
            int chain = tp[cur];
            while (big(stuf[chain]) && dep[stuf[chain].back().ff] <= dep[cur]) stuf[chain].pop_back();
            stuf[chain].push_back({cur,v});
            if (chain == 1) break;
            cur = par[chain];
        }
    };

    upd(1,c[1]);
    for (int i=1;i<n;i++) {
        auto[a,b] = edg[i-1];
        cout << qry(a,c[a]) << '\n';
        upd(b,c[b]);
    }
} 

signed main() {
    ios_base::sync_with_stdio(0); cin.tie(0);
    #ifdef Dodi
    freopen("in.txt", "r", stdin);
    freopen("out.txt", "w", stdout);
    #endif
    int t = 1;
    //cin >> t;
    while (t --> 0) solve();
}

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