#include #include 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 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; }