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Submission #987104

# Submission time Handle Problem Language Result Execution time Memory
987104 2024-05-21T21:44:50 Z aykhn Spring cleaning (CEOI20_cleaning) C++17
100 / 100
 187 ms 31572 KB 
#include <bits/stdc++.h>
 
using namespace std;
 
#define int long long
#define inf 0x3F3F3F3F3F3F3F3F
 
struct SegTree
{
    int sz;
    vector<int> st, lz;
    void init(int n)
    {
        sz = 1;
        while (sz < n) sz <<= 1;
        st.assign(sz << 1, 0);
        lz.assign(sz << 1, 0);
    }
    void relax(int l, int r, int x)
    {
        if (!lz[x]) return;
        st[x] = r - l - st[x];
        if (l + 1 == r)
        {
            lz[x] = 0;
            return;
        }
        lz[2*x + 1] ^= 1, lz[2*x + 2] ^= 1;
        lz[x] = 0;
    }
    void make(int l, int r, int x, int lx, int rx)
    {
        if (lx >= rx) return;
        relax(l, r, x);
        if (l >= rx || r <= lx) return;
        if (l >= lx && r <= rx)
        {
            lz[x] ^= 1;
            relax(l, r, x);
            return;
        }
        int mid = (l + r) >> 1;
        make(l, mid, 2*x + 1, lx, rx);
        make(mid, r, 2*x + 2, lx, rx);
        st[x] = st[2*x + 1] + st[2*x + 2];
    }
    int get(int l, int r, int x, int lx, int rx)
    {
        if (lx >= rx) return 0;
        if (l >= rx || r <= lx) return 0;
        relax(l, r, x);
        if (l >= lx && r <= rx) return st[x];
        int mid = (l + r) >> 1;
        return get(l, mid, 2*x + 1, lx, rx) + get(mid, r, 2*x + 2, lx, rx);
    }
};
 
const int MXN = 1e5 + 5;
 
int n, q, r, SZ;
vector<int> adj[MXN];
int head[MXN], val[MXN], sz[MXN], dep[MXN], par[MXN];
int in[MXN], out[MXN], tim = -1;
SegTree st;
 
void _dfs(int a, int p)
{
    sz[a] = 1;
    vector<int> nw;
    for (int v : adj[a])
    {
        if (v == p) continue;
        _dfs(v, a);
        nw.push_back(v);
        sz[a] += sz[v];
    }
    swap(nw, adj[a]);
    int mx = 0;
    for (int i = 0; i < adj[a].size(); i++)
    {
        if (sz[adj[a][i]] > sz[adj[a][mx]]) mx = i;
    }
    if (!adj[a].empty()) swap(adj[a][0], adj[a][mx]);
}
void dfs(int a)
{
    in[a] = ++tim;
    for (int i = 0; i < adj[a].size(); i++)
    {
        if (!i) head[adj[a][i]] = head[a];
        else head[adj[a][i]] = adj[a][i];
        dep[adj[a][i]] = dep[a] + 1;
        par[adj[a][i]] = a;
        dfs(adj[a][i]);
    }
    out[a] = tim;
}
int ans = 0;
 
void upd(int u, int v)
{
    while (head[u] != head[v])
    {
        if (dep[head[u]] < dep[head[v]]) swap(u, v);
        if (head[u] == u)
        {
            ans -= val[in[u]];
            val[in[u]] ^= 1;
            ans += val[in[u]];
            u = par[u];
        }
        else
        {
            st.make(0, SZ, 0, in[head[u]] + 1, in[u] + 1);
            u = head[u];
        }
    }
    if (dep[u] < dep[v]) swap(u, v);
    st.make(0, SZ, 0, in[v] + 1, in[u] + 1);
}
 
int cntleaf = 0;
int add[MXN];
 
signed main() 
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cin >> n >> q;
    for (int i = 1; i < n; i++)
    {
        int u, v;
        cin >> u >> v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }
    for (int i = 1; i <= n; i++) 
    {
        if (adj[i].size() >= 2) 
        {
            r = i;
            break;
        }
    }
    st.init(n);
    SZ = st.sz;
    _dfs(r, r);
    head[r] = r;
    dfs(r);
    for (int i = 1; i <= n; i++) 
    {
        cntleaf += adj[i].empty();
        if (adj[i].empty()) upd(r, i);
    }
    for (int i = 1; i <= q; i++)
    {
        set<int> s;
        int d;
        cin >> d;
        for (int j = 1; j <= d; j++)
        {
            int x;
            cin >> x;
            add[x] ^= 1;
            s.insert(x);
        }
        int nw = cntleaf;
        for (int j : s) nw -= adj[j].empty();
        if ((nw + d) & 1)
        {
            for (int j : s) add[j] = 0;
            cout << -1 << '\n';
            continue;
        }
        for (int j : s) 
        {
            if (adj[j].empty() && !add[j]) upd(r, j);
            else if (!adj[j].empty() && add[j]) upd(r, j);
        }
        int all = st.get(0, SZ, 0, 0, n);
        cout << (n - 1 - ans - all) * 2 + ans + all + d << '\n';
        for (int j : s) 
        {
            if (adj[j].empty() && !add[j]) upd(r, j);
            else if (!adj[j].empty() && add[j]) upd(r, j);
        }
        for (int j : s) add[j] = 0;
    }
}

Compilation message

cleaning.cpp: In function 'void _dfs(long long int, long long int)':
cleaning.cpp:79:23: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   79 |     for (int i = 0; i < adj[a].size(); i++)
      |                     ~~^~~~~~~~~~~~~~~
cleaning.cpp: In function 'void dfs(long long int)':
cleaning.cpp:88:23: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   88 |     for (int i = 0; i < adj[a].size(); i++)
      |                     ~~^~~~~~~~~~~~~~~

Subtask #1
0.0 / 0.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 8792 KB Output is correct
2 Correct 77 ms 10856 KB Output is correct

Subtask #2
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 9052 KB Output is correct
2 Correct 11 ms 9052 KB Output is correct
3 Correct 28 ms 16952 KB Output is correct
4 Correct 46 ms 16544 KB Output is correct
5 Correct 54 ms 17104 KB Output is correct

Subtask #3
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 15 ms 10228 KB Output is correct
2 Correct 12 ms 10076 KB Output is correct
3 Correct 50 ms 28628 KB Output is correct
4 Correct 131 ms 30152 KB Output is correct
5 Correct 37 ms 26968 KB Output is correct

Subtask #4
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 44 ms 12124 KB Output is correct
2 Correct 33 ms 10844 KB Output is correct
3 Correct 14 ms 10840 KB Output is correct
4 Correct 12 ms 11612 KB Output is correct
5 Correct 17 ms 12124 KB Output is correct
6 Correct 50 ms 11612 KB Output is correct

Subtask #5
19.0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 70 ms 14204 KB Output is correct
2 Correct 154 ms 15180 KB Output is correct
3 Correct 96 ms 12372 KB Output is correct
4 Correct 141 ms 15328 KB Output is correct
5 Correct 135 ms 15324 KB Output is correct

Subtask #6
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 187 ms 17188 KB Output is correct
2 Correct 143 ms 24256 KB Output is correct
3 Correct 173 ms 23500 KB Output is correct
4 Correct 99 ms 22864 KB Output is correct

Subtask #7
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 8792 KB Output is correct
2 Correct 77 ms 10856 KB Output is correct
3 Correct 11 ms 9052 KB Output is correct
4 Correct 11 ms 9052 KB Output is correct
5 Correct 28 ms 16952 KB Output is correct
6 Correct 46 ms 16544 KB Output is correct
7 Correct 54 ms 17104 KB Output is correct
8 Correct 15 ms 10228 KB Output is correct
9 Correct 12 ms 10076 KB Output is correct
10 Correct 50 ms 28628 KB Output is correct
11 Correct 131 ms 30152 KB Output is correct
12 Correct 37 ms 26968 KB Output is correct
13 Correct 44 ms 12124 KB Output is correct
14 Correct 33 ms 10844 KB Output is correct
15 Correct 14 ms 10840 KB Output is correct
16 Correct 12 ms 11612 KB Output is correct
17 Correct 17 ms 12124 KB Output is correct
18 Correct 50 ms 11612 KB Output is correct
19 Correct 70 ms 14204 KB Output is correct
20 Correct 154 ms 15180 KB Output is correct
21 Correct 96 ms 12372 KB Output is correct
22 Correct 141 ms 15328 KB Output is correct
23 Correct 135 ms 15324 KB Output is correct
24 Correct 187 ms 17188 KB Output is correct
25 Correct 143 ms 24256 KB Output is correct
26 Correct 173 ms 23500 KB Output is correct
27 Correct 99 ms 22864 KB Output is correct
28 Correct 125 ms 14528 KB Output is correct
29 Correct 124 ms 24444 KB Output is correct
30 Correct 51 ms 18116 KB Output is correct
31 Correct 114 ms 31572 KB Output is correct
32 Correct 133 ms 15116 KB Output is correct
33 Correct 151 ms 21332 KB Output is correct
34 Correct 165 ms 23376 KB Output is correct
35 Correct 167 ms 23120 KB Output is correct