Submission #999096

#	Time	Username	Problem	Language	Result	Execution time	Memory
999096		Whisper	Construction of Highway (JOI18_construction)	C++17	0 / 100	195 ms	262144 KiB

construction

#include <bits/stdc++.h>

using namespace std;
using ll = long long;

//#define int long long
#define FOR(i, a, b) for (int i = (a); i <= (b); i++)
#define FORD(i, a, b) for (int i = (b); i >= (a); i --)
#define REP(i, n) for (int i = 0; i < (n); ++i)
#define REPD(i, n) for (int i = (n) - 1; i >= 0; --i)

#define MASK(i) (1LL << (i))
#define BIT(x, i) (((x) >> (i)) & 1)


constexpr ll LINF = (1ll << 60);
constexpr int INF = (1ll << 30);
constexpr int Mod = 1e9 + 7;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

/*
    Phu Trong from Nguyen Tat Thanh High School for gifted student
*/

template <class X, class Y>
    bool minimize(X &x, const Y &y){
        X eps = 1e-9;
        if (x > y + eps) {x = y; return 1;}
        return 0;
    }

template <class X, class Y>
    bool maximize(X &x, const Y &y){
        X eps = 1e-9;
        if (x + eps < y) {x = y; return 1;}
        return 0;
    }

#define MAX     100005
int numNode;
struct Edge{
    int u, v;
    Edge(){}
    Edge(int _u, int _v): u(_u), v(_v){}
    int other(int x){return (x ^ u ^ v);}
} edge[MAX];

vector<int> G[MAX];

int label[MAX]; // label(i) as liveness of i-th city

int dep[MAX], head[MAX], heavy[MAX], sz[MAX], pos[MAX], par[MAX];
int cnt = 0;
int pre_dfs(int u, int p = -1){
    sz[u] = 1;
    par[u] = p;
    int bigChild = 0;
    for (int &i : G[u]){
        int v = edge[i].other(u);
        if(v ^ p){
            dep[v] = dep[u] + 1;
            pre_dfs(v, u);
            sz[u] += sz[v];
            if (sz[bigChild] < sz[v]){
                bigChild = v, heavy[u] = v;
            }
        }
    }
}
deque<pair<int, int>> group[MAX];
void decompose(int u, int p = 1){
    pos[u] = ++cnt;
    group[p].push_back(make_pair(label[u], 1ll));
    head[u] = p;
    if(heavy[u]) decompose(heavy[u], p);
    for (int &i : G[u]){
        int v = edge[i].other(u);
        if (v ^ par[u]) if(v ^ heavy[u]){
            decompose(v, v);
            //make new chain
        }
    }
}
#define All(x) (x).begin(), (x).end()


struct FenwickTree{
    int *F = nullptr;
    int n;
    vector<pair<int, int>> rollback;
    void init (int _n = 0){
        this -> n = _n;
        F = new int[n + 5];
        fill(F, F + n + 1, 0);
    }

    void upd(int p, int val){
        if (val > 0) rollback.push_back(make_pair(p, -val));
        for (; p > 0; p -= p & (-p)) F[p] += val;
    }
    int query(int p){
        int res = 0;
        for (; p <= n; p += p & (-p)) res += F[p];
        return res;
    }
    void undo(void){
        while ((int)rollback.size()){
            upd(rollback.back().first, rollback.back().second);
            rollback.pop_back();
        }
    }
} fen;
int ans;
void addEdge(int u, int v){
    vector<pair<int, int>> upd;
    ans = 0;
    while (u > 0){
        vector<pair<int, int>> nw_upd;
        int length = dep[u] - dep[head[u]] + 1;
        while (length > 0 && (int)group[head[u]].size()){
            if (length >= group[head[u]].front().second){
                length -= group[head[u]].front().second;
                nw_upd.emplace_back(group[head[u]].front());
                group[head[u]].pop_front();
            }
            else{
                group[head[u]].front().second -= length;
                nw_upd.emplace_back(group[head[u]].front().first, length);
                length = 0;
            }
        }
        group[head[u]].push_front(make_pair(label[v], dep[u] - dep[head[u]] + 1));
        reverse(All(nw_upd));
        for (auto&j : nw_upd) upd.push_back(j);
        u = par[head[u]];
    }
    reverse(All(upd));
    for (pair<int, int>&x : upd){
        int val = x.first, cnt = x.second;
        ans += fen.query(val + 1) * cnt;
        fen.upd(val, cnt);
    }
    fen.undo();
}

void process(void){
    cin >> numNode;
    for (int i = 1; i <= numNode; ++i) cin >> label[i];
    for (int i = 1; i < numNode; ++i){
        cin >> edge[i].u >> edge[i].v;
        G[edge[i].u].emplace_back(i);
        G[edge[i].v].emplace_back(i);
    }
    vector<int> comp;
    for (int i = 1; i <= numNode; ++i) comp.push_back(label[i]);
    sort(All(comp));
    for (int i = 1; i <= numNode; ++i) label[i] = lower_bound(All(comp), label[i]) - comp.begin() + 1;

    pre_dfs(1);
    decompose(1);
    fen.init(numNode);
    for (int i = 1; i < numNode; ++i){
        int u = edge[i].u, v = edge[i].v;
        addEdge(u, v);
        cout << ans << '\n';
    }
}

signed main(){
    #define name "Whisper"
    cin.tie(nullptr) -> sync_with_stdio(false);
    //freopen(name".inp", "r", stdin);
    //freopen(name".out", "w", stdout);

    process();

}

Compilation message (stderr)

construction.cpp: In function 'int pre_dfs(int, int)':
construction.cpp:69:1: warning: no return statement in function returning non-void [-Wreturn-type]
   69 | }
      | ^

• Subtask 1: 0 / 7
• Subtask 2: 0 / 9
• Subtask 3: 0 / 84