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https://git.sb/baoshuo/OI-codes.git
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106 lines
2.0 KiB
C++
106 lines
2.0 KiB
C++
#include <cstdlib>
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#include <iostream>
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using std::cin;
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using std::cout;
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#define endl '\n'
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const int N = 1e5 + 5;
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int n, m, l, r, root, cnt;
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struct node {
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int l, r, s, v, k;
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bool d;
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node()
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: l(0), r(0), s(0), v(0), d(false), k(rand()) {}
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node(int _v)
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: l(0), r(0), s(1), v(_v), d(false), k(rand()) {}
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} tr[N];
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void pushup(int u) {
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tr[u].s = tr[tr[u].l].s + tr[tr[u].r].s + 1;
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}
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void pushdown(int u) {
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if (tr[u].d) {
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tr[u].d = false;
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tr[tr[u].l].d ^= 1;
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tr[tr[u].r].d ^= 1;
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std::swap(tr[u].l, tr[u].r);
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}
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}
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int build(int l, int r) {
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if (l > r) return 0;
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int mid = l + r >> 1;
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int p = ++cnt;
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tr[p] = node(mid - 1);
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tr[p].l = build(l, mid - 1);
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tr[p].r = build(mid + 1, r);
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pushup(p);
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return p;
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}
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std::pair<int, int> split(int p, int k) {
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if (!p) return std::make_pair(0, 0);
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pushdown(p);
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if (k <= tr[tr[p].l].s) {
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auto o = split(tr[p].l, k);
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tr[p].l = o.second;
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pushup(p);
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o.second = p;
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return o;
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}
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auto o = split(tr[p].r, k - tr[tr[p].l].s - 1);
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tr[p].r = o.first;
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pushup(p);
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o.first = p;
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return o;
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}
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int merge(int x, int y) {
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if (!x || !y) return x | y;
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pushdown(x);
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pushdown(y);
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if (tr[x].k > tr[y].k) {
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tr[x].r = merge(tr[x].r, y);
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pushup(x);
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return x;
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}
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tr[y].l = merge(x, tr[y].l);
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pushup(y);
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return y;
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}
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void reserve(int l, int r) {
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auto x = split(root, r + 1);
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auto y = split(x.first, l);
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tr[y.second].d ^= 1;
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root = merge(merge(y.first, y.second), x.second);
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}
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void print(int p) {
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if (!p) return;
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pushdown(p);
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print(tr[p].l);
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if (1 <= tr[p].v && tr[p].v <= n) {
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cout << tr[p].v << ' ';
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}
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print(tr[p].r);
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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 >> n >> m;
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root = build(1, n + 2);
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while (m--) {
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cin >> l >> r;
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reserve(l, r);
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}
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print(root);
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cout << endl;
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return 0;
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}
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