Submission #924044

#	Time	Username	Problem	Language	Result	Execution time	Memory
924044		Whisper	Janjetina (COCI21_janjetina)	C++17	110 / 110	556 ms	60420 KiB

Main

#include <bits/stdc++.h>

using namespace std;
using ll = long long;
using ld = long double;
using T = tuple<ll, ll, ll>;

#define int long long
#define Base 41
#define sz(a) (int)a.size()
#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 all(x) x.begin() , x.end()
#define pii pair<int , int>
#define fi first
#define se second
#define Lg(x) 31 - __builtin_clz(x)

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

constexpr ll LINF = (1ll << 60);
constexpr int INF = (1ll << 30);
constexpr int MAX = 2e5 + 5;
constexpr int Mod = 1e9 + 7;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

void setupIO(){
    #define name "Whisper"
    //Phu Trong from Nguyen Tat Thanh High School for gifted student
    srand(time(NULL));
    cin.tie(nullptr)->sync_with_stdio(false); cout.tie(nullptr);
    //freopen(name".inp", "r", stdin);
    //freopen(name".out", "w", stdout);
    cout << fixed << setprecision(10);
}

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;
    }

int numNode, K;
vector<pii> adj[MAX];
int sz[MAX], del[MAX];

void reSubsize(int u, int p){
    sz[u] = 1;
    for (auto&[v, w] : adj[u]) if(v ^ p){
        if (!del[v]){
            reSubsize(v, u); sz[u] += sz[v];
        }
    }
}
int getCentroid(int u, int p, int siz){
    for (auto&[v, w] : adj[u]) if(v ^ p){
        if (sz[v] * 2 > siz && !del[v]) return getCentroid(v, u, siz);
    }
    return u;
}

//>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

struct FenwickTree{
    int n = 2 * MAX - 5;
    int f[2 * MAX]{0};
    vector<int> opt;
    void modify(int p, int val){
        if (val > 0) opt.push_back(p);
        for (; p <= n; p += p & (-p)) f[p] += val;
    }
    int query(int p){
        int res = 0;
        for ( ; p > 0; p -= p & (-p)) res += f[p];
        return res;
    }
    void clear(){
        while (opt.size()){
            int p = opt.back(); opt.pop_back();
            modify(p, -1);
        }
    }
} fen;

int ans = 0;
vector<pii> subtree;

void dfs(int u, int p, int mxValue, int dep){
    if (dep > 0)
        subtree.emplace_back(mxValue, dep);
    for (auto&[v, w] : adj[u]) if(v ^ p){
        if (del[v]) continue;
        int nxt = max(mxValue, w);
        dfs(v, u, nxt, dep + 1);
    }
}

void compute(int val, int ok){
    sort(all(subtree));

    for (auto&[w, l] : subtree){
        int needL = w - K - l;
        if (w - l >= K) ans += ok;
        ans += fen.query(needL) * val;
        fen.modify(l, 1);
    }
    for (auto&[w, l] : subtree){
        fen.modify(l, -1);
    }
    subtree.clear();
}
void decompose(int root){
    reSubsize(root, -1);
    int siz = sz[root];
    root = getCentroid(root, -1, siz);
    dfs(root, -1, 0, 0);
    compute(1, 1);
    for (auto&[v, w] : adj[root]) if(!del[v]){
        dfs(v, root, w, 1);
        compute(-1, 0);
    }
    del[root] = 1;
    for (auto&[v, w] : adj[root]) if (!del[v]){
        decompose(v);
    }
}
//count the number from (x -> y) that the difference of the max weight and the length of the path >= K
void Whisper(){
    cin >> numNode >> K;
    for (int i = 1; i < numNode; ++i){
        int u, v, w; cin >> u >> v >> w;
        adj[u].emplace_back(v, w);
        adj[v].emplace_back(u, w);
    }
    decompose(1);
    cout << ans * 2;
}


signed main(){
    setupIO();
    int Test = 1;
//    cin >> Test;
    for ( int i = 1 ; i <= Test ; i++ ){
        Whisper();
        if (i < Test) cout << '\n';
    }
}

• Subtask 1: 15 / 15
• Subtask 2: 35 / 35
• Subtask 3: 60 / 60