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| #include <iostream>
#include <cstdio>
#include <cctype>
#define maxn 100010
#define gc getchar
#define INF 2000000000
using namespace std;
int read() {
int x = 0, f = 0; char c = gc();
while (!isdigit(c)) f |= c == '-', c = gc();
while (isdigit(c)) x = x * 10 + c - '0', c = gc();
return f ? -x : x;
}
int n, m;
#define lc T[i].ch[0]
#define rc T[i].ch[1]
struct Splay {
int v, sz, ch[2]; bool rev;
} T[maxn]; int top, rt, f[maxn];
inline void update(int i) { T[i].sz = 1 + T[lc].sz + T[rc].sz; }
inline void Update(int i) { swap(lc, rc); T[i].rev ^= 1; }
inline void pushdown(int i) {
bool &rev = T[i].rev; if (!rev) return ;
Update(lc); Update(rc); rev = 0;
}
inline int get(int i) { return i == T[f[i]].ch[1]; }
inline void rotate(int x) {
int fa = f[x], ffa = f[f[x]], wx = get(x);
f[x] = ffa; f[T[x].ch[wx ^ 1]] = fa; f[fa] = x;
if (ffa) T[ffa].ch[T[ffa].ch[1] == fa] = x;
T[fa].ch[wx] = T[x].ch[wx ^ 1]; T[x].ch[wx ^ 1] = fa;
update(fa); update(x);
}
void Splay(int i, int k = 0) {
for (int fa = f[i]; fa != k; rotate(i), fa = f[i])
if (f[fa] != k) rotate(get(i) == get(fa) ? fa : i);
if (!k) rt = i;
}
void build(int &i, int l, int r, int fa) {
if (l > r) return ; i = ++top;
int m = l + r >> 1;
build(lc, l, m - 1, i); build(rc, m + 1, r, i);
T[i].v = m; T[i].sz = 1; f[i] = fa; update(i);
}
int findk(int k) {
int i = rt;
while (1) { pushdown(i);
if (k <= T[lc].sz) { i = lc; continue; }
k -= T[lc].sz; if (k <= 1) return Splay(i), i;
--k; i = rc;
}
}
inline void solve() {
int l = read(), r = read(), i; l = findk(l); r = findk(r + 2);
Splay(l, 0); Splay(r, l); Update(T[r].ch[0]);
}
void print(int i) {
if (!i) return; pushdown(i);
print(lc); if (1 <= T[i].v && T[i].v <= n) printf("%d ", T[i].v); print(rc);
}
int main() {
n = read(); m = read(); build(rt, 0, n + 1, 0);
for (int i = 1; i <= m; ++i) solve(); print(rt);
return 0;
}
|