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답안 #511199

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
511199 2022-01-15T11:57:01 Z Victor Janjetina (COCI21_janjetina) C++17
15 / 110
 1500 ms 5068 KB 
// #pragma GCC target ("avx,avx2,fma")
// #pragma GCC optimize ("Ofast,inline") // O1 - O2 - O3 - Os - Ofast
// #pragma GCC optimize ("unroll-loops")
#include <bits/stdc++.h>

using namespace std;

#define rep(i, a, b) for (int i = (a); i < (b); ++i)
#define per(i, a, b) for (int i = (b - 1); i >= (a); --i)
#define trav(a, x) for (auto &a : x)

#define all(x) x.begin(), x.end()
#define sz(x) x.size()
#define pb push_back
#define debug(x) cout << #x << " = " << x << endl

#define umap unordered_map
#define uset unordered_set

typedef pair<int, int> ii;
typedef pair<int, ii> iii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<vi> vvi;

typedef long long ll;
typedef pair<ll, ll> pll;
typedef vector<ll> vll;
typedef vector<pll> vpll;

const int INF = 1'000'000'007;

struct Node {
    Node *l, *r;
    int lo, hi, val, mset = INF, madd = 0;
    Node(int L, int R) : lo(L), hi(R) {
        val = 0;
        if (hi - lo != 1) {
            int mid = (lo + hi) / 2;
            l = new Node(lo, mid);
            r = new Node(mid, hi);
        }
    }

    int query(int L, int R) {
        if (hi <= L || R <= lo) return 0;
        if (L <= lo && hi <= R) return val;
        push();
        return l->query(L, R) + r->query(L, R);
    }

    void add(int L, int R, int x) {
        if (hi <= L || R <= lo) return;
        if (L <= lo && hi <= R) {
            if (mset != INF)
                mset += x;
            else
                madd += x;

            val += x * (hi - lo);
            return;
        }
        push();
        l->add(L, R, x);
        r->add(L, R, x);
        val = l->val + r->val;
    }

    void set(int L, int R, int x) {
        if (hi <= L || R <= lo) return;
        if (L <= lo && hi <= R) {
            mset = x;
            val = x * (hi - lo);
            madd = 0;
            return;
        }
        push();
        l->set(L, R, x);
        r->set(L, R, x);
        val = l->val + r->val;
    }

    void push() {
        if (mset != INF) {
            l->set(lo, hi, mset);
            r->set(lo, hi, mset);
            mset = INF;

        } else if (madd) {
            l->add(lo, hi, madd);
            r->add(lo, hi, madd);
            madd = 0;
        }
    }
};

bitset<100005> removed;
Node *segtree;
int n, k, subsize[100005], centroid, cnt = 0;
vii graph[100005];

void dfs(int u, int p) {
    subsize[u] = 1;
    int mx = 0;
    trav(edge, graph[u]) {
        int v, w;
        tie(v, w) = edge;
        if (v != p && !removed[v]) {
            dfs(v, u);
            subsize[u] += subsize[v];
            mx = max(mx, subsize[v]);
        }
    }

    if (subsize[u] >= (cnt + 1) / 2 && mx <= cnt / 2) centroid = u;
}

ll pairs(vii &paths) {
    sort(all(paths));
    segtree->set(0, n, 0);

    ll ans = 0;
    trav(path, paths) {
        int mx, dist;
        tie(mx, dist) = path;
        // cout << "mx = " << mx << " dist = " << dist << " pairs = " << segtree->query(0, mx - dist - k) << endl << endl;
        ans += segtree->query(0, mx - dist - k);
        segtree->add(dist, dist + 1, 1);
    }

    return ans;
}

ll ans = 0;
vii paths, subpaths;
void dfs2(int u, int p, int mx_road, int dist) {
    paths.emplace_back(mx_road, dist);
    if (u != centroid) subpaths.emplace_back(mx_road, dist);

    trav(edge, graph[u]) {
        int v, w;
        tie(v, w) = edge;
        if (v != p && !removed[v]) {
            dfs2(v, u, max(mx_road, w), dist + 1);
            if (u == centroid) {
                ans -= pairs(subpaths);
                subpaths.clear();
            }
        }
    }
}

void predfs(int u,int p) {
    ++cnt;
    trav(edge,graph[u]){
        int v=edge.first;
        if(v!=p&&!removed[v])predfs(v,u);
    }
}

void centroid_decomp(int u) {
    cnt=0;
    dfs(u, u);
    if (subsize[u] == 1) return;
    assert(!removed[centroid]);

    dfs2(centroid, centroid, 0, 0);
    ans += pairs(paths);
    paths.clear();

    removed[centroid] = 1;
    trav(edge, graph[centroid]) {
        int v, w;
        tie(v, w) = edge;
        if (!removed[v]) centroid_decomp(v);
    }
}

int main() {
    cin.tie(0)->sync_with_stdio(0);
    cin.exceptions(cin.failbit);

    cin >> n >> k;
    segtree = new Node(0, n);
    --k;
    rep(i, 1, n) {
        int u, v, w;
        cin >> u >> v >> w;
        graph[--u].emplace_back(--v, w);
        graph[v].emplace_back(u, w);
    }

    centroid_decomp(0);
    cout << ans * 2 << endl;
    return 0;
}

Subtask #1
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 2668 KB Output is correct
2 Correct 1 ms 2668 KB Output is correct
3 Correct 3 ms 2636 KB Output is correct
4 Correct 178 ms 2896 KB Output is correct
5 Correct 95 ms 2892 KB Output is correct
6 Correct 189 ms 2896 KB Output is correct
7 Correct 97 ms 2892 KB Output is correct
8 Correct 174 ms 2892 KB Output is correct
9 Correct 100 ms 2852 KB Output is correct
10 Correct 134 ms 2840 KB Output is correct
11 Correct 151 ms 2828 KB Output is correct
12 Correct 108 ms 2836 KB Output is correct
13 Correct 153 ms 2836 KB Output is correct
14 Correct 169 ms 2956 KB Output is correct
15 Correct 92 ms 2852 KB Output is correct
16 Correct 138 ms 3052 KB Output is correct
17 Correct 102 ms 2840 KB Output is correct
18 Correct 154 ms 2840 KB Output is correct
19 Correct 166 ms 2848 KB Output is correct
20 Correct 107 ms 2948 KB Output is correct
21 Correct 159 ms 2848 KB Output is correct
22 Correct 168 ms 2764 KB Output is correct

Subtask #2
0 / 35.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 2636 KB Output is correct
2 Correct 1 ms 2668 KB Output is correct
3 Correct 3 ms 2636 KB Output is correct
4 Correct 193 ms 2892 KB Output is correct
5 Execution timed out 1589 ms 5068 KB Time limit exceeded
6 Halted 0 ms 0 KB -

Subtask #3
0 / 60.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 2668 KB Output is correct
2 Correct 1 ms 2668 KB Output is correct
3 Correct 3 ms 2636 KB Output is correct
4 Correct 178 ms 2896 KB Output is correct
5 Correct 95 ms 2892 KB Output is correct
6 Correct 189 ms 2896 KB Output is correct
7 Correct 97 ms 2892 KB Output is correct
8 Correct 174 ms 2892 KB Output is correct
9 Correct 100 ms 2852 KB Output is correct
10 Correct 134 ms 2840 KB Output is correct
11 Correct 151 ms 2828 KB Output is correct
12 Correct 108 ms 2836 KB Output is correct
13 Correct 153 ms 2836 KB Output is correct
14 Correct 169 ms 2956 KB Output is correct
15 Correct 92 ms 2852 KB Output is correct
16 Correct 138 ms 3052 KB Output is correct
17 Correct 102 ms 2840 KB Output is correct
18 Correct 154 ms 2840 KB Output is correct
19 Correct 166 ms 2848 KB Output is correct
20 Correct 107 ms 2948 KB Output is correct
21 Correct 159 ms 2848 KB Output is correct
22 Correct 168 ms 2764 KB Output is correct
23 Correct 1 ms 2636 KB Output is correct
24 Correct 1 ms 2668 KB Output is correct
25 Correct 3 ms 2636 KB Output is correct
26 Correct 193 ms 2892 KB Output is correct
27 Execution timed out 1589 ms 5068 KB Time limit exceeded
28 Halted 0 ms 0 KB -