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https://git.sb/baoshuo/OI-codes.git
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91 lines
1.7 KiB
C++
91 lines
1.7 KiB
C++
#include <iostream>
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#include <algorithm>
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#include <vector>
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using std::cin;
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using std::cout;
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const char endl = '\n';
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const int N = 2e5 + 5;
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int n, m, a[N];
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int cnt, root[N];
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std::vector<int> nums;
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struct node {
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int l, r, c;
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} tr[N << 5];
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int build(int l, int r) {
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int p = ++cnt;
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if (l == r) return p;
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int mid = l + r >> 1;
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tr[p].l = build(l, mid);
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tr[p].r = build(mid + 1, r);
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return p;
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}
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int insert(int p, int l, int r, int x) {
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int q = ++cnt;
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tr[q] = tr[p];
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if (l == r) {
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tr[q].c++;
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return q;
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}
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int mid = l + r >> 1;
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if (x <= mid) tr[q].l = insert(tr[q].l, l, mid, x);
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else tr[q].r = insert(tr[q].r, mid + 1, r, x);
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tr[q].c = tr[tr[q].l].c + tr[tr[q].r].c;
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return q;
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}
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int query(int p, int q, int l, int r, int x) {
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if (l == r) return l;
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int c = tr[tr[p].l].c - tr[tr[q].l].c;
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int mid = l + r >> 1;
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if (x <= c) return query(tr[p].l, tr[q].l, l, mid, x);
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return query(tr[p].r, tr[q].r, mid + 1, r, x - c);
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}
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int main() {
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std::ios::sync_with_stdio(false);
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cin.tie(nullptr);
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cin >> n >> m;
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for (int i = 1; i <= n; i++) {
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cin >> a[i];
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nums.emplace_back(a[i]);
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}
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std::sort(nums.begin(), nums.end());
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nums.erase(std::unique(nums.begin(), nums.end()), nums.end());
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root[0] = build(0, nums.size() - 1);
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for (int i = 1; i <= n; i++) {
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root[i] = insert(root[i - 1], 0, nums.size() - 1, std::lower_bound(nums.begin(), nums.end(), a[i]) - nums.begin());
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}
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while (m--) {
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int l, r, k;
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cin >> l >> r >> k;
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cout << nums.at(query(root[r], root[l - 1], 0, nums.size() - 1, k)) << endl;
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}
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return 0;
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}
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