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답안 #944941

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
944941 2024-03-13T08:29:40 Z thinknoexit Transport (COCI19_transport) C++17
130 / 130
 313 ms 18636 KB 
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int N = 100100;
vector<pair<int, int>> adj[N];
ll ans = 0;
bool vis[N];
int sz[N], m;
ll now[N], fw[N], a[N];
vector<ll> f, c;
int dfs_sz(int v, int p = -1) {
    sz[v] = 1;
    for (auto& [x, w] : adj[v]) {
        if (x == p || vis[x]) continue;
        sz[v] += dfs_sz(x, v);
    }
    return sz[v];
}
int centroid(int v, int p, int s) {
    for (auto& [x, w] : adj[v]) {
        if (x == p || vis[x]) continue;
        if (sz[x] > s) return centroid(x, v, s);
    }
    return v;
}
void init(int v, int p, ll sum, ll d) {
    if (d >= 0) ans++;
    f.push_back(-d);
    sum += a[v];
    for (auto& [x, w] : adj[v]) {
        if (x == p || vis[x]) continue;
        init(x, v, sum - w, min(d, sum - w));
    }
}
void add(int v, int p, ll sum, ll d) {
    int idx = upper_bound(c.begin(), c.end(), -d) - c.begin();
    for (int i = idx;i <= m;i += i & -i) fw[i]++;
    sum += a[v];
    for (auto& [x, w] : adj[v]) {
        if (x == p || vis[x]) continue;
        int W = a[v] - w;
        add(x, v, sum - w, min(d, sum - w));
    }
}
void rem(int v, int p, ll sum, ll d) {
    int idx = upper_bound(c.begin(), c.end(), -d) - c.begin();
    for (int i = idx;i <= m;i += i & -i) fw[i]--;
    sum += a[v];
    for (auto& [x, w] : adj[v]) {
        if (x == p || vis[x]) continue;
        rem(x, v, sum - w, min(d, sum - w));
    }
}
void cal(int v, int p, ll sum, ll mn) {
    if (mn >= 0) {
        int idx = upper_bound(c.begin(), c.end(), sum) - c.begin();
        for (int i = idx;i > 0;i -= i & -i) ans += fw[i];
    }
    for (auto& [x, w] : adj[v]) {
        if (x == p || vis[x]) continue;
        ll W = a[x] - w;
        cal(x, v, sum + W, min(mn + W, W));
    }
}
void decom(int v) {
    v = centroid(v, v, dfs_sz(v) / 2);
    vis[v] = 1;
    init(v, v, 0, 0);
    ans--;
    // compress
    sort(f.begin(), f.end());
    for (auto& x : f) {
        if (c.empty() || x != c.back()) c.push_back(x);
    }
    m = c.size();
    add(v, v, 0, 0);
    for (auto& [x, w] : adj[v]) {
        if (vis[x]) continue;
        rem(x, v, a[v] - w, min(0ll, a[v] - w));
        cal(x, v, a[x] - w, min(0ll, a[x] - w));
        add(x, v, a[v] - w, min(0ll, a[v] - w));
    }
    rem(v, v, 0, 0);
    f.clear();
    c.clear();
    for (auto& [x, w] : adj[v]) {
        if (!vis[x]) decom(x);
    }
}
int main() {
    cin.tie(nullptr)->sync_with_stdio(false);
    int n;
    cin >> n;
    for (int i = 1;i <= n;i++) cin >> a[i];
    for (int i = 1;i < n;i++) {
        int u, v, w;
        cin >> u >> v >> w;
        adj[u].push_back({ v, w });
        adj[v].push_back({ u, w });
    }
    decom(1);
    cout << ans;
    return 0;
}

Compilation message

transport.cpp: In function 'void add(int, int, ll, ll)':
transport.cpp:41:13: warning: unused variable 'W' [-Wunused-variable]
   41 |         int W = a[v] - w;
      |             ^

Subtask #1
13.0 / 13.0

# 결과 실행 시간 메모리 Grader output
1 Correct 8 ms 5464 KB Output is correct
2 Correct 7 ms 5812 KB Output is correct

Subtask #2
13.0 / 13.0

# 결과 실행 시간 메모리 Grader output
1 Correct 6 ms 5724 KB Output is correct
2 Correct 10 ms 6212 KB Output is correct

Subtask #3
13.0 / 13.0

# 결과 실행 시간 메모리 Grader output
1 Correct 65 ms 10200 KB Output is correct
2 Correct 77 ms 10976 KB Output is correct

Subtask #4
13.0 / 13.0

# 결과 실행 시간 메모리 Grader output
1 Correct 98 ms 11744 KB Output is correct
2 Correct 136 ms 14676 KB Output is correct

Subtask #5
13.0 / 13.0

# 결과 실행 시간 메모리 Grader output
1 Correct 139 ms 14284 KB Output is correct
2 Correct 249 ms 18636 KB Output is correct

Subtask #6
13.0 / 13.0

# 결과 실행 시간 메모리 Grader output
1 Correct 65 ms 7000 KB Output is correct
2 Correct 41 ms 7516 KB Output is correct

Subtask #7
13.0 / 13.0

# 결과 실행 시간 메모리 Grader output
1 Correct 60 ms 8148 KB Output is correct
2 Correct 124 ms 8916 KB Output is correct

Subtask #8
13.0 / 13.0

# 결과 실행 시간 메모리 Grader output
1 Correct 160 ms 8400 KB Output is correct
2 Correct 189 ms 10660 KB Output is correct

Subtask #9
13.0 / 13.0

# 결과 실행 시간 메모리 Grader output
1 Correct 225 ms 9604 KB Output is correct
2 Correct 245 ms 11560 KB Output is correct

Subtask #10
13.0 / 13.0

# 결과 실행 시간 메모리 Grader output
1 Correct 306 ms 10824 KB Output is correct
2 Correct 313 ms 12756 KB Output is correct