Submission #1262319

#	Time	Username	Problem	Language	Result	Execution time	Memory
1262319		son2008	Cats or Dogs (JOI18_catdog)	C++20	0 / 100	9 ms	19008 KiB

catdog

#include <bits/stdc++.h>
using namespace std;
#define ii pair<int, int>
#define fi first
#define se second
// #define int long long
#define ll long long
#define ld double
#define mp make_pair
#define lg2 30
#define iii pair<int, ii>
#define iiii pair<ii, ii>
#define base 29
#define eps 1e-8
#define MASK(i) (1LL << (i))
#define BIT(S, i) (((S) >> (i)) & 1)
int dx[] = {0LL, 0LL, 1, -1, 1, 1, -1, -1};
int dy[] = {1, -1, 0LL, 0LL, 1, -1, 1, -1};
const int maxn = 4e5 + 5;
const int mod = 1e9 + 7;
int n, dp[maxn][3], tt[maxn], sz[maxn], head[maxn], pos[maxn], siz[maxn], par[maxn];
vector<int> a[maxn];
void prepare(int u, int cha)
{
    sz[u] = 1;
    for (int v : a[u])
    {
        if (v == cha)
            continue;
        par[v] = u;
        sz[u] += sz[v];
        prepare(v, u);
    }
}
void hld(int u, int dau, int cha)
{
    cout<<u<<" "<<dau<<'\n';
    head[u] = dau;
    pos[u] = ++siz[dau];
    int bigchild = 0;
    for (int v : a[u])
    {
        if (v == cha)
            continue;
        if (sz[bigchild] < sz[v])
        {
            bigchild = v;
        }
    }
    if (bigchild)
        hld(bigchild, dau, u);
    for (int v : a[u])
    {
        if (v != bigchild && v != cha)
        {
            hld(v, v, u);
        }
    }
}
struct node
{
    int x[2][2];
    node()
    {
        for (int i = 0; i <= 1; i++)
        {
            for (int j = 0; j <= 1; j++)
            {
                x[i][j] = n;
            }
        }
    }
};
struct segmentree
{
    vector<node> tree;
    void init(int _n)
    {
        tree.resize(4 * n + 5);
    }
    node Merge(node &a, node &b)
    {
        node ans;
        for (int i = 0; i <= 1; i++)
        {
            for (int j = 0; j <= 1; j++)
            {
                for (int x = 0; x <= 1; x++)
                {
                    for (int y = 0; y <= 1; y++)
                    {
                        ans.x[i][y] = min(ans.x[i][y], a.x[i][j] + b.x[x][y] + (j != x));
                    }
                }
            }
        }
        return ans;
    }
    void build(int id, int l, int r)
    {
        if (l == r)
        {
            tree[id].x[1][1] = tree[id].x[0][0] = 0;
            return ;
        }
        int mid = (l + r) / 2;
        build(id * 2, l, mid);
        build(id * 2 + 1, mid + 1, r);
        tree[id] = Merge(tree[id * 2], tree[id * 2 + 1]);
    }
    void update(int id, int l, int r, int i, int cat, int dog)
    {
        if (l == r)
        {
            tree[id].x[0][0] += cat;
            tree[id].x[1][1] += dog;
            return;
        }
        int mid = (l + r) / 2;
        if (i <= mid)
            update(id * 2, l, mid, i, cat, dog);
        else
            update(id * 2 + 1, mid + 1, r, i, cat, dog);
        tree[id] = Merge(tree[id * 2], tree[id * 2 + 1]);
    }
    node get()
    {
        return tree[1];
    }
} st[maxn];
void update(int u, int cat, int dog)
{
    while (u)
    {
        node trc = st[head[u]].get();
        int trc_cat = min({trc.x[0][0], trc.x[0][1], trc.x[1][0] + 1, trc.x[1][1] + 1});
        int trc_dog = min({trc.x[1][1], trc.x[1][0], trc.x[0][1] + 1, trc.x[0][0] + 1});
        st[head[u]].update(1, 1, siz[head[u]], pos[u], cat, dog);
        trc = st[head[u]].get();
        int ht_cat = min({trc.x[0][0], trc.x[0][1], trc.x[1][0] + 1, trc.x[1][1] + 1});
        int ht_dog = min({trc.x[1][1], trc.x[1][0], trc.x[0][1] + 1, trc.x[0][0] + 1});
        cat = ht_cat - trc_cat;
        dog = ht_dog - trc_dog;
        u = par[head[u]];
    }
}
int getans()
{
    return min({st[1].tree[1].x[0][1], st[1].tree[1].x[1][0], st[1].tree[1].x[1][1], st[1].tree[1].x[0][0]});
}
int cat(int v)
{
    tt[v] = 1;
    update(v, 0, n);
    return getans();
}
int dog(int v)
{
    tt[v] = 2;
    update(v, n, 0);
    return getans();
}
int neighbor(int v)
{
    if (tt[v] == 1)
    {
        update(v, 0, -n);
    }
    else
        update(v, -n, 0);
    tt[v] = 0;
    return getans();
}
void initialize(int N, vector<int> A, vector<int> B)
{
    n = N;
    for (int i = 0; i < n - 1; i++)
    {
        a[A[i]].push_back(B[i]);
        a[B[i]].push_back(A[i]);
    }
    prepare(1, -1);
    hld(1, 1, -1);
    for (int i = 1; i <= n; i++)
    {
        if (head[i] == i)
        {
            st[i].init(siz[i]);
            st[i].build(1, 1, siz[i]);
        }
    }
}
/*signed main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
#define task "task"
    if (fopen(task ".inp", "r"))
    {
        freopen(task ".inp", "r", stdin);
        freopen(task ".out", "w", stdout);
    }
    initialize(3, {1, 2}, {2, 3});
    cout << cat(1) << " ";
    cout << cat(3) << " ";
    cout << dog(2) << " ";
    cout << neighbor(2);
    cerr << endl
         << "TIME : " << clock() * 0.001 << "s" << endl;
}
*/

• Subtask 1: 0 / 8
• Subtask 2: 0 / 30
• Subtask 3: 0 / 62