mirror of
https://git.sb/baoshuo/OI-codes.git
synced 2024-12-13 06:26:26 +00:00
106 lines
2.0 KiB
C++
106 lines
2.0 KiB
C++
#include <cstdlib>
|
|
#include <iostream>
|
|
|
|
using std::cin;
|
|
using std::cout;
|
|
#define endl '\n'
|
|
|
|
const int N = 1e5 + 5;
|
|
|
|
int n, m, l, r, root, cnt;
|
|
|
|
struct node {
|
|
int l, r, s, v, k;
|
|
bool d;
|
|
|
|
node()
|
|
: l(0), r(0), s(0), v(0), d(false), k(rand()) {}
|
|
node(int _v)
|
|
: l(0), r(0), s(1), v(_v), d(false), k(rand()) {}
|
|
} tr[N];
|
|
|
|
void pushup(int u) {
|
|
tr[u].s = tr[tr[u].l].s + tr[tr[u].r].s + 1;
|
|
}
|
|
|
|
void pushdown(int u) {
|
|
if (tr[u].d) {
|
|
tr[u].d = false;
|
|
tr[tr[u].l].d ^= 1;
|
|
tr[tr[u].r].d ^= 1;
|
|
std::swap(tr[u].l, tr[u].r);
|
|
}
|
|
}
|
|
|
|
int build(int l, int r) {
|
|
if (l > r) return 0;
|
|
int mid = l + r >> 1;
|
|
int p = ++cnt;
|
|
tr[p] = node(mid - 1);
|
|
tr[p].l = build(l, mid - 1);
|
|
tr[p].r = build(mid + 1, r);
|
|
pushup(p);
|
|
return p;
|
|
}
|
|
|
|
std::pair<int, int> split(int p, int k) {
|
|
if (!p) return std::make_pair(0, 0);
|
|
pushdown(p);
|
|
if (k <= tr[tr[p].l].s) {
|
|
auto o = split(tr[p].l, k);
|
|
tr[p].l = o.second;
|
|
pushup(p);
|
|
o.second = p;
|
|
return o;
|
|
}
|
|
auto o = split(tr[p].r, k - tr[tr[p].l].s - 1);
|
|
tr[p].r = o.first;
|
|
pushup(p);
|
|
o.first = p;
|
|
return o;
|
|
}
|
|
|
|
int merge(int x, int y) {
|
|
if (!x || !y) return x | y;
|
|
pushdown(x);
|
|
pushdown(y);
|
|
if (tr[x].k > tr[y].k) {
|
|
tr[x].r = merge(tr[x].r, y);
|
|
pushup(x);
|
|
return x;
|
|
}
|
|
tr[y].l = merge(x, tr[y].l);
|
|
pushup(y);
|
|
return y;
|
|
}
|
|
|
|
void reserve(int l, int r) {
|
|
auto x = split(root, r + 1);
|
|
auto y = split(x.first, l);
|
|
tr[y.second].d ^= 1;
|
|
root = merge(merge(y.first, y.second), x.second);
|
|
}
|
|
|
|
void print(int p) {
|
|
if (!p) return;
|
|
pushdown(p);
|
|
print(tr[p].l);
|
|
if (1 <= tr[p].v && tr[p].v <= n) {
|
|
cout << tr[p].v << ' ';
|
|
}
|
|
print(tr[p].r);
|
|
}
|
|
|
|
int main() {
|
|
std::ios::sync_with_stdio(false);
|
|
cin >> n >> m;
|
|
root = build(1, n + 2);
|
|
while (m--) {
|
|
cin >> l >> r;
|
|
reserve(l, r);
|
|
}
|
|
print(root);
|
|
cout << endl;
|
|
return 0;
|
|
}
|