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답안 #1092529

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
1092529 2024-09-24T10:26:01 Z onbert Mergers (JOI19_mergers) C++17
0 / 100
 91 ms 72088 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

# 결과 실행 시간 메모리 Grader output
1 Correct 14 ms 35676 KB Output is correct
2 Correct 15 ms 35596 KB Output is correct
3 Correct 15 ms 35676 KB Output is correct
4 Correct 15 ms 35708 KB Output is correct
5 Correct 14 ms 35676 KB Output is correct
6 Correct 14 ms 35676 KB Output is correct
7 Correct 14 ms 35676 KB Output is correct
8 Correct 15 ms 35676 KB Output is correct
9 Correct 16 ms 35780 KB Output is correct
10 Correct 17 ms 35676 KB Output is correct
11 Correct 17 ms 35672 KB Output is correct
12 Correct 19 ms 35676 KB Output is correct
13 Correct 16 ms 35676 KB Output is correct
14 Correct 18 ms 35676 KB Output is correct
15 Correct 16 ms 35676 KB Output is correct
16 Runtime error 46 ms 72088 KB Execution killed with signal 6
17 Halted 0 ms 0 KB -

Subtask #2
0 / 24.0

# 결과 실행 시간 메모리 Grader output
1 Correct 14 ms 35676 KB Output is correct
2 Correct 15 ms 35596 KB Output is correct
3 Correct 15 ms 35676 KB Output is correct
4 Correct 15 ms 35708 KB Output is correct
5 Correct 14 ms 35676 KB Output is correct
6 Correct 14 ms 35676 KB Output is correct
7 Correct 14 ms 35676 KB Output is correct
8 Correct 15 ms 35676 KB Output is correct
9 Correct 16 ms 35780 KB Output is correct
10 Correct 17 ms 35676 KB Output is correct
11 Correct 17 ms 35672 KB Output is correct
12 Correct 19 ms 35676 KB Output is correct
13 Correct 16 ms 35676 KB Output is correct
14 Correct 18 ms 35676 KB Output is correct
15 Correct 16 ms 35676 KB Output is correct
16 Runtime error 46 ms 72088 KB Execution killed with signal 6
17 Halted 0 ms 0 KB -

Subtask #3
0 / 14.0

# 결과 실행 시간 메모리 Grader output
1 Correct 14 ms 35676 KB Output is correct
2 Correct 15 ms 35596 KB Output is correct
3 Correct 15 ms 35676 KB Output is correct
4 Correct 15 ms 35708 KB Output is correct
5 Correct 14 ms 35676 KB Output is correct
6 Correct 14 ms 35676 KB Output is correct
7 Correct 14 ms 35676 KB Output is correct
8 Correct 15 ms 35676 KB Output is correct
9 Correct 16 ms 35780 KB Output is correct
10 Correct 17 ms 35676 KB Output is correct
11 Correct 17 ms 35672 KB Output is correct
12 Correct 19 ms 35676 KB Output is correct
13 Correct 16 ms 35676 KB Output is correct
14 Correct 18 ms 35676 KB Output is correct
15 Correct 16 ms 35676 KB Output is correct
16 Runtime error 46 ms 72088 KB Execution killed with signal 6
17 Halted 0 ms 0 KB -

Subtask #4
0 / 22.0

# 결과 실행 시간 메모리 Grader output
1 Correct 64 ms 66632 KB Output is correct
2 Correct 90 ms 71108 KB Output is correct
3 Correct 19 ms 36700 KB Output is correct
4 Correct 18 ms 36700 KB Output is correct
5 Correct 16 ms 35676 KB Output is correct
6 Correct 19 ms 35796 KB Output is correct
7 Correct 18 ms 36624 KB Output is correct
8 Correct 91 ms 68408 KB Output is correct
9 Incorrect 18 ms 36700 KB Output isn't correct
10 Halted 0 ms 0 KB -

Subtask #5
0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 14 ms 35676 KB Output is correct
2 Correct 15 ms 35596 KB Output is correct
3 Correct 15 ms 35676 KB Output is correct
4 Correct 15 ms 35708 KB Output is correct
5 Correct 14 ms 35676 KB Output is correct
6 Correct 14 ms 35676 KB Output is correct
7 Correct 14 ms 35676 KB Output is correct
8 Correct 15 ms 35676 KB Output is correct
9 Correct 16 ms 35780 KB Output is correct
10 Correct 17 ms 35676 KB Output is correct
11 Correct 17 ms 35672 KB Output is correct
12 Correct 19 ms 35676 KB Output is correct
13 Correct 16 ms 35676 KB Output is correct
14 Correct 18 ms 35676 KB Output is correct
15 Correct 16 ms 35676 KB Output is correct
16 Runtime error 46 ms 72088 KB Execution killed with signal 6
17 Halted 0 ms 0 KB -