Submission #1078315

#	Time	Username	Problem	Language	Result	Execution time	Memory
1078315		cpptowin	Abracadabra (CEOI22_abracadabra)	C++17	100 / 100	694 ms	125148 KiB

Main

#include <bits/stdc++.h>
#define fo(i, d, c) for (int i = d; i <= c; i++)
#define fod(i, c, d) for (int i = c; i >= d; i--)
#define maxn 1000010
#define N 1010
#define fi first
#define se second
#define pb emplace_back
#define en cout << "\n";
#define int long long
#define inf (int)1e18
#define bitcount(x) __builtin_popcountll(x)
#define pii pair<int, int>
#define vii vector<pii>
#define lb(x) x & -x
#define bit(i, j) ((i >> j) & 1)
#define offbit(i, j) (i ^ (1LL << j))
#define onbit(i, j) (i | (1LL << j))
#define vi vector<int>
#define all(x) x.begin(), x.end()
#define ss(x) (int)x.size()
template <typename T1, typename T2>
bool minimize(T1 &a, T2 b)
{
    if (a > b)
    {
        a = b;
        return true;
    }
    return false;
}
template <typename T1, typename T2>
bool maximize(T1 &a, T2 b)
{
    if (a < b)
    {
        a = b;
        return true;
    }
    return false;
}
using namespace std;
const int nsqrt = 450;
const int mod = 1e9 + 7;
void add(int &x, int k)
{
    x += k;
    x %= mod;
    if (x < 0)
        x += mod;
}
void del(int &x, int k)
{
    x -= k;
    x %= mod;
    if (x < 0)
        x += mod;
}
struct SegmentTree
{
    vector<int> st;
    int n;
    /// real n
    SegmentTree(int _n = 0) : n(_n)
    {
        st.resize(4 * n + 10);
    }
    void resize(int _n)
    {
        n = _n;
        st.resize(4 * n + 10);
    }
    void update(int id, int l, int r, int x, int val)
    {
        if (x > r or x < l)
            return;
        if (l == r)
        {
            st[id] += val;
            return;
        }
        int mid = (l + r) >> 1;
        update(id << 1, l, mid, x, val);
        update(id << 1 | 1, mid + 1, r, x, val);
        st[id] = st[id << 1] + st[id << 1 | 1];
    }
    void assign(int id, int l, int r, int x, int val)
    {
        if (x > r or x < l)
            return;
        if (l == r)
        {
            st[id] = val;
            return;
        }
        int mid = (l + r) >> 1;
        assign(id << 1, l, mid, x, val);
        assign(id << 1 | 1, mid + 1, r, x, val);
        st[id] = st[id << 1] + st[id << 1 | 1];
    }
    int get(int id, int l, int r, int u, int v)
    {
        if (l > v || u > r)
            return 0;
        if (u <= l && r <= v)
            return st[id];
        int mid = (l + r) >> 1;
        return get(id << 1, l, mid, u, v) + get(id << 1 | 1, mid + 1, r, u, v);
    }
    int walkright(int id, int l, int r, int x, int val)
    {
        if (st[id] < val)
            return -1;
        if (r < x)
            return -1;
        if (l == r)
            return l;
        int mid = l + r >> 1;
        int ans = -1;
        if (st[id << 1] >= val)
            return walkright(id << 1, l, mid, x, val);
        return walkright(id << 1 | 1, mid + 1, r, x, val - st[id << 1]);
    }
    int get(int l, int r)
    {
        return get(1, 1, n, l, r);
    }
    void update(int x, int val)
    {
        update(1, 1, n, x, val);
    }
    void assign(int x, int val)
    {
        assign(1, 1, n, x, val);
    }
    int walkright(int x, int val)
    {
        return walkright(1, 1, n, x, val);
    }
} t(maxn);
void R(int a[], int n, int ans[])
{
    stack<int> st;
    fod(i, n, 1)
    {
        while (st.size() and a[st.top()] <= a[i])
            st.pop();
        ans[i] = (st.empty() ? n + 1 : st.top());
        st.push(i);
    }
}
int n, q, a[maxn];
vii qry[maxn];
int r[maxn];
int pos[maxn];
int res[maxn];
set<array<int, 3>> st;
void calc(int ff)
{
    for (auto [p, id] : qry[ff])
    {
        int x = t.walkright(1, p);
        int p1 = p - t.get(1, x - 1);
        res[id] = a[pos[x] + p1 - 1];
    }
}
main()
{
#define name "TASK"
    if (fopen(name ".inp", "r"))
    {
        freopen(name ".inp", "r", stdin);
        freopen(name ".out", "w", stdout);
    }
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cin >> n >> q;
    t.resize(n);
    fo(i, 1, n) cin >> a[i], pos[a[i]] = i;
    fo(i, 1, q)
    {
        int t, u;
        cin >> t >> u;
        if (t == 0)
            res[i] = a[u];
        else
            qry[min(n, t)].pb(u, i);
    }
    R(a, n, r);
    int id = 1;
    while (id <= n)
    {
        st.insert({a[id], id, r[id] - 1});
        t.assign(a[id], r[id] - id);
        id = r[id];
    }
    // for(auto [v,l,r] : st) cout << v << ' ' << l << ' ' << r << "\n";en;
    fo(i, 1, n)
    {
        int p = t.walkright(1, n / 2);
        if (t.get(1, p) > n / 2)
        {
            int p1 = n / 2 - t.get(1, p - 1);
            int ff = t.get(p, p);
            auto lb = st.find({p, pos[p], pos[p] + ff - 1});
            if (lb != st.end())
                st.erase(lb);
            st.insert({p, pos[p], pos[p] + p1 - 1});
            t.assign(p, p1);
            int ind = pos[p] + p1;
            // if(i == 2) cout << p << ' ' << p1 << ' ' << ff << ' ' << r[ind] << "\n";
            while (ind <= pos[p] + ff - 1)
            {
                int pos1 = min(r[ind] - 1,pos[p] + ff - 1);
                st.insert({a[ind], ind, pos1});
                t.assign(a[ind], pos1 - ind + 1);
                ind = r[ind];
            }
        }
        calc(i);
        // for(auto [v,l,r] : st) cout << v << ' ' << l << ' ' << r << "\n";en;
    }
    fo(i, 1, q) cout << res[i] << "\n";
}

Compilation message (stderr)

Main.cpp: In member function 'long long int SegmentTree::walkright(long long int, long long int, long long int, long long int, long long int)':
Main.cpp:118:21: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  118 |         int mid = l + r >> 1;
      |                   ~~^~~
Main.cpp:119:13: warning: unused variable 'ans' [-Wunused-variable]
  119 |         int ans = -1;
      |             ^~~
Main.cpp: At global scope:
Main.cpp:167:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
  167 | main()
      | ^~~~
Main.cpp: In function 'int main()':
Main.cpp:172:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  172 |         freopen(name ".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:173:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  173 |         freopen(name ".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 40 / 40
• Subtask 3: 25 / 25
• Subtask 4: 25 / 25