Submission #872081

#	Time	Username	Problem	Language	Result	Execution time	Memory
872081		sleepntsheep	Ball Machine (BOI13_ballmachine)	C++17	0 / 100	16 ms	8476 KiB

ballmachine

#include <iostream>
#include <bitset>
#include <cstring>
#include <vector>
#include <algorithm>
#include <deque>
#include <set>
#include <utility>
#include <array>

using i64 = long long;
using u64 = unsigned long long;
using f64 = double;
using f80 = long double;

using namespace std;
#define ALL(x) x.begin(), x.end()
#define ShinLena cin.tie(nullptr)->sync_with_stdio(false);
#define N 100000

int root, n, q, L[N], J[N], P[N], alloc, ta[N], h[N], tin[N], rv[N], timer, t[N<<1];
char lz[N];
struct { int v, l; } g[N-1];

inline void link(int u, int v) {
    if (h[u]) g[++alloc] = {v, 0}, g[ta[u]].l = alloc, ta[u] = alloc;
    else g[++alloc] = {v, h[u]}, h[u] = ta[u] = alloc;
}

inline void push(int v, int l, int r)
{
    if (-1 == lz[v]) return;
    t[v] = lz[v] * (r-l+1);
    if (l != r) 
    {
        int m = (l+r)/2, vl=v+1, vr=v+(m-l+1)*2;
        lz[vl] = lz[vr] = lz[v];
    }
    lz[v] = -1;
}

int qry(int x, int y, int v = 0, int l = 0, int r = n - 1)
{
    push(v, l, r);
    if (y < l || r < x) return 0;
    if (x <= l && r <= y) return t[v];
    int m = (l+r)/2, vl =v + 1, vr=v+(m-l+1)*2;
    return qry(x, y, vl, l, m) + qry(x, y, vr, m+1, r);
}

int qry(int u) { return qry(tin[u], tin[u]); }

void update(int x, int y, int k, int v = 0, int l = 0, int r = n - 1)
{
    push(v, l, r);
    if (y < l || r < x) return;
    int m = (l+r)/2, vl =v + 1, vr=v+(m-l+1)*2;
    if (x <= l && r <= y) {lz[v] = k; push(v, l, r); return; }
    update(x, y, k, vl, l, m), update(x, y, k, vr, m+1, r);
    t[v] = t[vl]+t[vr];
}

void dfs(int u)
{
    for (auto j = h[u]; j; j = g[j].l)
    {
        P[g[j].v] = u;
        if (L[u] - L[J[u]] == L[J[u]] - L[J[J[u]]]) J[g[j].v] = J[J[u]];
        else J[g[j].v] = u;
        L[g[j].v] = L[u] + 1;
        dfs(g[j].v);
    }
    rv[tin[u] = timer++] = u;
}

int highest(int u)
{
    for (; u != P[u]; )
    {
        if (qry(J[u])) u = J[u];
        else if (qry(P[u])) u = P[u];
        else break;
    }
    return u;
}

int main()
{
    ShinLena;
    cin >> n >> q;
    for (int i = 0; i < n; ++i) cin >> P[i], (P[i] ? link(P[i]-1, i) : void(P[root = i] = root));
    memset(lz, -1, sizeof lz);
    dfs(0);
    return 0;
    for (int t, k; q--;)
    {
        cin >> t >> k;
        if (t == 1)
        {
            int l = 0, r = n - 1;
            while (l <= r)
            {
                int m = (l+r)/2;
                if (qry(0, m) <= k) l = m + 1;
                else r = m - 1;
            }
            cout << rv[l-1] + 1 << '\n';
            update(0, l-1, 1);
        }
        else
        {
            int r = highest(k-1);
            update(tin[r], tin[r], 0);
            cout << L[k-1] - L[r] << '\n';
        }
    }

    return 0;
}

Compilation message (stderr)

ballmachine.cpp: In function 'int main()':
ballmachine.cpp:91:84: warning: operation on 'root' may be undefined [-Wsequence-point]
   91 |     for (int i = 0; i < n; ++i) cin >> P[i], (P[i] ? link(P[i]-1, i) : void(P[root = i] = root));
      |                                                                               ~~~~~^~~
ballmachine.cpp:91:84: warning: operation on 'root' may be undefined [-Wsequence-point]

• Subtask 1: 0 / 25
• Subtask 2: 0 / 30
• Subtask 3: 0 / 40
• Subtask 4: 0 / 5