Submission #1302685

#TimeUsernameProblemLanguageResultExecution timeMemory
1302685Jawad_Akbar_JJAbracadabra (CEOI22_abracadabra)C++20
100 / 100
419 ms35584 KiB
#include <iostream>
#include <vector>

using namespace std;
const int N = 1<<18;
int ft[N], a[N], Ans[N<<2], b[N], sz[N], st[N], Nxt[N];
vector<pair<int, int>> Qr[N];
vector<int> stk;

void Add(int i, int v){
	sz[i] += v;
	for (; i < N; i += i&-i)
		ft[i] += v;
}

int get(int i, int ans = 0){
	for (; i; i -= i&-i)
		ans += ft[i];
	return ans;
}

int get2(int k, int i = 1){
	while (1){
		if (ft[i + (i&-i)] < k)
			i += i&-i;
		else if (ft[i] >= k)
			return i-1;
		else
			k -= ft[i++];
	}
	return -1;
}

int main(){
	ios_base::sync_with_stdio(false); cin.tie(NULL);
	int n, q;
	cin>>n>>q;

	for (int i=1;i<=n;i++)
		cin>>a[i];

	for (int i=1, t, id;i<=q;i++){
		cin>>t>>id;
		t = min(t, n);
		if (t == 0)
			Ans[i] = a[id];
		else
			Qr[t].push_back({id, i});
	}

	int l1 = 1, l2 = n / 2 + 1, m = 0, ind = 0;
	while (ind < n){
		if (l1 <= n / 2 and (l2 == n + 1 or a[l2] > a[l1]))
			b[++ind] = a[l1++];
		else
			b[++ind] = a[l2++];

		st[b[ind]] = ind;
		m = max(m, b[ind]);
		Add(m, 1);
	}
	
	for (int i=1;i<=n;i++){
		while (stk.size() > 0 and b[stk.back()] < b[i])
			Nxt[stk.back()] = i, stk.pop_back();
		stk.push_back(i), Nxt[i] = n + 1;
	}

	for (int i=1;i<=n;i++){
		for (auto [id, id2] : Qr[i]){
			int k = get2(id) + 1, rem = id - get(k - 1);
			Ans[id2] = b[st[k] + rem - 1];
		}

		int k = get2(n / 2) + 1, rem = get(k) - n / 2;

		for (int j=st[k] + sz[k] - rem;j < st[k] + sz[k];j = Nxt[j])
			Add(b[j], min(sz[k] + st[k], Nxt[j]) - j);
		Add(k, -rem);		
	}

	for (int i=1;i<=q;i++)
		cout<<Ans[i]<<'\n';
}
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