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Submission #1092530

# Submission time Handle Problem Language Result Execution time Memory
1092530 2024-09-24T10:26:19 Z onbert Mergers (JOI19_mergers) C++17
0 / 100
 88 ms 69312 KB 
#include <bits/stdc++.h>
using namespace std;
#define int long long
const int maxn = 5e5 + 5, maxk = 5e5+5, lg = 20;
int n, k;
vector<int> ADJ[maxn];
int A[maxn];

int SZ[maxn], FA[maxn], newid[maxn], lim[maxn], cnt = 0;
bool cmp(int x, int y) {
    return SZ[x] > SZ[y];
}
void DFS0(int u) {
    SZ[u] = 1;
    for (int v:ADJ[u]) {
        FA[v] = u;
        ADJ[v].erase(find(ADJ[v].begin(), ADJ[v].end(), u));
        DFS0(v);
        SZ[u] += SZ[v];
    }
    sort(ADJ[u].begin(), ADJ[u].end(), cmp);
}
void DFS1(int u) {
    cnt++;
    newid[u] = cnt;
    for (int v:ADJ[u]) DFS1(v);
    lim[newid[u]] = cnt;
}

vector<int> adj[maxn];
int fa[maxn], sz[maxn];
vector<int> mem[maxk];
int a[maxn];

int st[maxn][lg];
void dfs0(int u) {
    for (int i=1;i<lg;i++) {
        if (!st[u][i-1] || !st[st[u][i-1]][i-1]) break;
        st[u][i] = st[st[u][i-1]][i-1];
    }
    for (int v:adj[u]) {
        st[v][0] = u;
        dfs0(v);
    }
}

int psum[maxn];
int lca(int u, int c) {
    int l = mem[c][0], r = mem[c].back();
    for (int i=lg-1;i>=0;i--) if (st[u][i]) {
        int v = st[u][i];
        if (!(v<=l && r<=lim[v])) u = v;
    }
    // cout << c << " " << l << " " << r << endl;
    if (!(u<=l && r<=lim[u])) u = fa[u];
    return u;
}

bool sep[maxn];
bool sepleaf[maxn];

int sum[maxn];
int dead = 0, ans = 0;

void dfs1(int u, int minus) {
    assert(sum[lim[u]] - sum[u] - minus > 0);
    if (sum[lim[u]] - sum[u] - minus <= 0) return;
    if (minus==0 && sep[u]) dead++;
    if (adj[u].size()==0) return;
    vector<pair<int,int>> vec;
    for (int v:adj[u]) {
        vec.push_back({sum[lim[v]] - sum[v-1], v});
    }
    sort(vec.begin(), vec.end());
    int l = 0, r = 1e18;
    while (l<r) {
        int mid = (l+r)/2, used = 0;
        for (auto [x, y]:vec) used += max(x - mid, (int)0);
        if (used <= minus) r = mid;
        else l = mid+1;
    }
    for (auto &[x, y]:vec) x = min(x, l);
    int total = sum[lim[u]] - sum[u] - minus;
    if (vec[0].first <= (total+1)/2) {
        ans += (total+1)/2;
        return;
    }
    int rest = total - vec[0].first;
    int v = vec[0].second;
    ans += rest;
    dfs1(v, rest);
}


signed main() {
    ios::sync_with_stdio(0); cin.tie(0);
    cin >> n >> k;
    for (int i=1;i<=n-1;i++) {
        int u, v;
        cin >> u >> v;
        ADJ[u].push_back(v), ADJ[v].push_back(u);
    }
    for (int i=1;i<=n;i++) cin >> A[i];
    DFS0(1);
    DFS1(1);
    // for (int i=1;i<=n;i++) cout << newid[i] << " "; cout << endl;
    // for (int i=1;i<=n;i++) cout << lim[i] << " "; cout << endl;
    for (int i=1;i<=n;i++) {
        for (int j:ADJ[i]) adj[newid[i]].push_back(newid[j]);
        if (i!=1) fa[newid[i]] = newid[FA[i]];
        else fa[i] = 0;
        sz[newid[i]] = SZ[i];
    }
    for (int i=1;i<=n;i++) {
        a[newid[i]] = A[i];
        mem[A[i]].push_back(newid[i]);
    }
    dfs0(1);
    for (int i=1;i<=k;i++) {
        sort(mem[i].begin(), mem[i].end());
        psum[lca(mem[i][0], i)] += mem[i].size();
    }
    for (int i=1;i<=n;i++) psum[i] += psum[i-1];

    for (int i=2;i<=n;i++) {
        sep[i] = (psum[lim[i]] - psum[i-1] == lim[i] - i + 1);
        // cout << psum[lim[i]] - psum[i-1] << " " << lim[i] - i + 1 << endl;
    }
    // for (int i=1;i<=n;i++) cout << sep[i]; cout << endl;
    
    for (int i=1;i<=n;i++) sum[i] = sum[i-1] + sep[i];

    for (int i=1;i<=n;i++) sepleaf[i] = (sep[i] && sum[lim[i]] - sum[i-1] == 1);
    for (int i=1;i<=n;i++) sum[i] = sum[i-1] + sepleaf[i];
    if (sum[n]==0) {
        cout << 0 << endl;
        return 0;
    }
    dfs1(1, 0);
    // assert(dead<=1);
    cout << ans + (dead+1)/2 << endl;
}

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 20 ms 35676 KB Output is correct
2 Correct 17 ms 35676 KB Output is correct
3 Correct 16 ms 35596 KB Output is correct
4 Correct 16 ms 35672 KB Output is correct
5 Correct 17 ms 35712 KB Output is correct
6 Correct 17 ms 35672 KB Output is correct
7 Correct 16 ms 35676 KB Output is correct
8 Correct 15 ms 35676 KB Output is correct
9 Correct 15 ms 35676 KB Output is correct
10 Correct 17 ms 35676 KB Output is correct
11 Correct 16 ms 35676 KB Output is correct
12 Correct 16 ms 35676 KB Output is correct
13 Correct 16 ms 35748 KB Output is correct
14 Correct 16 ms 35604 KB Output is correct
15 Correct 24 ms 35676 KB Output is correct
16 Correct 17 ms 35592 KB Output is correct
17 Correct 16 ms 35676 KB Output is correct
18 Correct 17 ms 35708 KB Output is correct
19 Correct 18 ms 35676 KB Output is correct
20 Incorrect 17 ms 35676 KB Output isn't correct
21 Halted 0 ms 0 KB -

Subtask #2
0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 20 ms 35676 KB Output is correct
2 Correct 17 ms 35676 KB Output is correct
3 Correct 16 ms 35596 KB Output is correct
4 Correct 16 ms 35672 KB Output is correct
5 Correct 17 ms 35712 KB Output is correct
6 Correct 17 ms 35672 KB Output is correct
7 Correct 16 ms 35676 KB Output is correct
8 Correct 15 ms 35676 KB Output is correct
9 Correct 15 ms 35676 KB Output is correct
10 Correct 17 ms 35676 KB Output is correct
11 Correct 16 ms 35676 KB Output is correct
12 Correct 16 ms 35676 KB Output is correct
13 Correct 16 ms 35748 KB Output is correct
14 Correct 16 ms 35604 KB Output is correct
15 Correct 24 ms 35676 KB Output is correct
16 Correct 17 ms 35592 KB Output is correct
17 Correct 16 ms 35676 KB Output is correct
18 Correct 17 ms 35708 KB Output is correct
19 Correct 18 ms 35676 KB Output is correct
20 Incorrect 17 ms 35676 KB Output isn't correct
21 Halted 0 ms 0 KB -

Subtask #3
0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 20 ms 35676 KB Output is correct
2 Correct 17 ms 35676 KB Output is correct
3 Correct 16 ms 35596 KB Output is correct
4 Correct 16 ms 35672 KB Output is correct
5 Correct 17 ms 35712 KB Output is correct
6 Correct 17 ms 35672 KB Output is correct
7 Correct 16 ms 35676 KB Output is correct
8 Correct 15 ms 35676 KB Output is correct
9 Correct 15 ms 35676 KB Output is correct
10 Correct 17 ms 35676 KB Output is correct
11 Correct 16 ms 35676 KB Output is correct
12 Correct 16 ms 35676 KB Output is correct
13 Correct 16 ms 35748 KB Output is correct
14 Correct 16 ms 35604 KB Output is correct
15 Correct 24 ms 35676 KB Output is correct
16 Correct 17 ms 35592 KB Output is correct
17 Correct 16 ms 35676 KB Output is correct
18 Correct 17 ms 35708 KB Output is correct
19 Correct 18 ms 35676 KB Output is correct
20 Incorrect 17 ms 35676 KB Output isn't correct
21 Halted 0 ms 0 KB -

Subtask #4
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 63 ms 65160 KB Output is correct
2 Correct 88 ms 69312 KB Output is correct
3 Correct 19 ms 36700 KB Output is correct
4 Correct 18 ms 36624 KB Output is correct
5 Correct 17 ms 35676 KB Output is correct
6 Correct 14 ms 35676 KB Output is correct
7 Correct 15 ms 36444 KB Output is correct
8 Correct 84 ms 66768 KB Output is correct
9 Incorrect 18 ms 36444 KB Output isn't correct
10 Halted 0 ms 0 KB -

Subtask #5
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 20 ms 35676 KB Output is correct
2 Correct 17 ms 35676 KB Output is correct
3 Correct 16 ms 35596 KB Output is correct
4 Correct 16 ms 35672 KB Output is correct
5 Correct 17 ms 35712 KB Output is correct
6 Correct 17 ms 35672 KB Output is correct
7 Correct 16 ms 35676 KB Output is correct
8 Correct 15 ms 35676 KB Output is correct
9 Correct 15 ms 35676 KB Output is correct
10 Correct 17 ms 35676 KB Output is correct
11 Correct 16 ms 35676 KB Output is correct
12 Correct 16 ms 35676 KB Output is correct
13 Correct 16 ms 35748 KB Output is correct
14 Correct 16 ms 35604 KB Output is correct
15 Correct 24 ms 35676 KB Output is correct
16 Correct 17 ms 35592 KB Output is correct
17 Correct 16 ms 35676 KB Output is correct
18 Correct 17 ms 35708 KB Output is correct
19 Correct 18 ms 35676 KB Output is correct
20 Incorrect 17 ms 35676 KB Output isn't correct
21 Halted 0 ms 0 KB -