oj.uz

Submission #391500

# Submission time Handle Problem Language Result Execution time Memory
391500 2021-04-18T23:36:54 Z benedict0724 Mergers (JOI19_mergers) C++17
0 / 100
 117 ms 57648 KB 
#include <bits/stdc++.h>

using namespace std;
vector<int> adj[500002], col[500002], tree[500002];
vector<pair<int, int>> edge;
int anc[500002], co[500002], d[500002], spr[500002][20];
int link[500002], lcacol[500002];
int ans = 0;

int _find(int x)
{
    if(x == link[x]) return x;
    return link[x] = _find(link[x]);
}
void _unite(int x, int y)
{
    x = _find(x);
    y = _find(y);

    link[x] = y;
}

void dep(int x, int p)
{
    for(int i : adj[x])
    {
        if(i == p) continue;
        d[i] = d[x] + 1;
        spr[i][0] = x;
        dep(i, x);
    }
}

void init(int n)
{
    for(int t=1;t<20;t++) for(int i=1;i<=n;i++)
        spr[i][t] = spr[spr[i][t-1]][t-1];
}

int lca(int a, int b)
{
    if(d[a] < d[b]) swap(a, b);
    int dif = d[a] - d[b];
    for(int i=19;i>=0;i--) if((1<<i) & dif) a = spr[a][i];
    if(a == b) return a;

    for(int i=19;i>=0;i--)
    {
        if(spr[a][i] != spr[b][i] && spr[a][i] != 0 && spr[b][i] != 0)
        {
            a = spr[a][i];
            b = spr[b][i];
        }
    }

    return spr[a][0];
}


int dfs(int x, int p)
{
    int ret = lcacol[co[x]];
    for(int i : adj[x])
    {
        if(i == p) continue;

        int tmp = dfs(i, x);
        if(tmp > d[x]) edge.push_back({i, x});
        else _unite(i, x);

        ret = min(ret, tmp);
    }

    return ret;
}

void solve(int x, int p)
{
    int ret = 0;
    for(int i : tree[x])
    {
        if(i == p) continue;
        solve(i, x);
        ret++;
    }

    ans += ret/2;
    if(p == -1 && ret%2 == 1) ans++;
}

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(NULL);
    int n, k; cin >> n >> k;
    for(int i=1;i<n;i++)
    {
        int s, e; cin >> s >> e;
        adj[s].push_back(e);
        adj[e].push_back(s);
    }

    for(int i=1;i<=n;i++) link[i] = i;

    d[1] = 1; dep(1, -1); init(n);

    for(int i=1;i<=n;i++)
    {
        int c; cin >> c;
        co[i] = c;
        col[c].push_back(i);
    }

    for(int i=1;i<=k;i++)
    {
        lcacol[i] = col[i][0];
        for(int j = 1; j < col[i].size();j++)
        {
            lcacol[i] = lca(lcacol[i], col[i][j]);
        }
        lcacol[i] = d[lcacol[i]];
    }

    dfs(1, -1);

    for(auto u : edge)
    {
        int s = u.first, e = u.second;

        s = _find(s); e = _find(e);

        tree[s].push_back(e);
        tree[e].push_back(s);
    }

    solve(_find(1), -1);

    cout << ans;
}

Compilation message

mergers.cpp: In function 'int main()':
mergers.cpp:117:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  117 |         for(int j = 1; j < col[i].size();j++)
      |                        ~~^~~~~~~~~~~~~~~

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 23 ms 35532 KB Output is correct
2 Correct 23 ms 35532 KB Output is correct
3 Correct 22 ms 35576 KB Output is correct
4 Correct 23 ms 35508 KB Output is correct
5 Correct 22 ms 35544 KB Output is correct
6 Correct 23 ms 35532 KB Output is correct
7 Correct 24 ms 35592 KB Output is correct
8 Correct 23 ms 35532 KB Output is correct
9 Correct 23 ms 35568 KB Output is correct
10 Correct 23 ms 35548 KB Output is correct
11 Correct 23 ms 35592 KB Output is correct
12 Incorrect 23 ms 35524 KB Output isn't correct
13 Halted 0 ms 0 KB -

Subtask #2
0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 23 ms 35532 KB Output is correct
2 Correct 23 ms 35532 KB Output is correct
3 Correct 22 ms 35576 KB Output is correct
4 Correct 23 ms 35508 KB Output is correct
5 Correct 22 ms 35544 KB Output is correct
6 Correct 23 ms 35532 KB Output is correct
7 Correct 24 ms 35592 KB Output is correct
8 Correct 23 ms 35532 KB Output is correct
9 Correct 23 ms 35568 KB Output is correct
10 Correct 23 ms 35548 KB Output is correct
11 Correct 23 ms 35592 KB Output is correct
12 Incorrect 23 ms 35524 KB Output isn't correct
13 Halted 0 ms 0 KB -

Subtask #3
0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 23 ms 35532 KB Output is correct
2 Correct 23 ms 35532 KB Output is correct
3 Correct 22 ms 35576 KB Output is correct
4 Correct 23 ms 35508 KB Output is correct
5 Correct 22 ms 35544 KB Output is correct
6 Correct 23 ms 35532 KB Output is correct
7 Correct 24 ms 35592 KB Output is correct
8 Correct 23 ms 35532 KB Output is correct
9 Correct 23 ms 35568 KB Output is correct
10 Correct 23 ms 35548 KB Output is correct
11 Correct 23 ms 35592 KB Output is correct
12 Incorrect 23 ms 35524 KB Output isn't correct
13 Halted 0 ms 0 KB -

Subtask #4
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 96 ms 50072 KB Output is correct
2 Correct 117 ms 57648 KB Output is correct
3 Incorrect 26 ms 36052 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #5
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 23 ms 35532 KB Output is correct
2 Correct 23 ms 35532 KB Output is correct
3 Correct 22 ms 35576 KB Output is correct
4 Correct 23 ms 35508 KB Output is correct
5 Correct 22 ms 35544 KB Output is correct
6 Correct 23 ms 35532 KB Output is correct
7 Correct 24 ms 35592 KB Output is correct
8 Correct 23 ms 35532 KB Output is correct
9 Correct 23 ms 35568 KB Output is correct
10 Correct 23 ms 35548 KB Output is correct
11 Correct 23 ms 35592 KB Output is correct
12 Incorrect 23 ms 35524 KB Output isn't correct
13 Halted 0 ms 0 KB -