oj.uz

Submission #341094

# Submission time Handle Problem Language Result Execution time Memory
341094 2020-12-29T01:56:54 Z ijxjdjd Mergers (JOI19_mergers) C++14
0 / 100
 143 ms 27748 KB 
#include <bits/stdc++.h>
using namespace std;

using ll = long long;
const int MAXN = (int)(5e5) + 5;
vector<int> adj[MAXN];
int up[MAXN][21];
int timer = 0;
int tin[MAXN];
int tout[MAXN];
int S[MAXN];
int last[MAXN];
int lcm[MAXN];
int cnt[MAXN];
void root(int n, int p) {
    tin[n] = timer++;
    up[n][0] = p;
    for (int k = 1; k <= 20; k++) {
        up[n][k] = up[up[n][k-1]][k-1];
    }
    for (int e : adj[n]) {
        if (e != p) {
            root(e, n);
        }
    }
    tout[n] = timer++;
}
int dfs(int n, int p) {
    int paths = 0;
    for (int e : adj[n]) {
        if (e != p) {
            paths += dfs(e, n);
            cnt[n] += cnt[e];
        }
    }
    if (cnt[n] == 0) {
        if (paths == 0 && n != p) {
            paths++;
        }
    }
    return paths;
}
bool is_ancestor(int a, int b) {
    return (tin[a] <= tin[b] && tout[a] >= tout[b]);
}
int lca(int a, int b) {
    if (is_ancestor(a, b)) {
        return a;
    }
    if (is_ancestor(b, a)) {
        return b;
    }
    int u = a;
    for (int k = 20; k >= 0; k--) {
        if (!is_ancestor(up[u][k], b)) {
            u = up[u][k];
        }
    }
    return up[u][0];
}
int main() {
//    string s = "input.in";
//    freopen(s.c_str(), "r", stdin);
    int N, s;
    cin >> N >> s;
    for (int i = 0; i < N-1; i++) {
        int a, b;
        cin >> a >> b;
        a--, b--;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }
    vector<int> df;
    for (int i = 0; i < N; i++) {
        df.push_back(i);
        last[i] = -1;
        cin >> S[i];
    }
    root(0, 0);
    sort(df.begin(), df.end(), [](const int& lhs, const int& rhs) {
            return tin[lhs] < tin[rhs];
         }
     );
    for (int i : df) {
        if (last[S[i]] == -1) {
            last[S[i]] = i;
            lcm[S[i]] = i;
        }
        else {
            if (is_ancestor(lcm[S[i]], i)) {
                cnt[i]++;
                cnt[lcm[S[i]]]--;
            }
            else {
                int lc = lca(lcm[S[i]], i);
                cnt[S[i]]++;
                cnt[lc]-=2;
                cnt[i]++;
                lcm[S[i]] = lc;
            }
        }
    }
    cout << (dfs(0, 0)+1)/2;
    return 0;
}

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 12140 KB Output is correct
2 Incorrect 9 ms 12140 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #2
0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 12140 KB Output is correct
2 Incorrect 9 ms 12140 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #3
0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 12140 KB Output is correct
2 Incorrect 9 ms 12140 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #4
0 / 22.0

# Verdict Execution time Memory Grader output
1 Incorrect 143 ms 27748 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #5
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 12140 KB Output is correct
2 Incorrect 9 ms 12140 KB Output isn't correct
3 Halted 0 ms 0 KB -