_bzoj3223 Tyvj 1729 文艺平衡树【Splay】

传送门：http://www.lydsy.com/JudgeOnline/problem.php?id=3223

裸的，打个标记。

#include <cstdio>
#include <algorithm>

const int maxn = 100005;

int n, m, stk[maxn], top, t1, t2;
int fa[maxn], ch[maxn][2], root, siz[maxn];
char rev[maxn];

inline void pushdown(int x) {
if (rev[x]) {
rev[x] = 0;
rev[ch[x][0]] ^= 1;
rev[ch[x][1]] ^= 1;
std::swap(ch[x][0], ch[x][1]);
}
}
inline void pushup(int x) {
siz[x] = siz[ch[x][0]] + siz[ch[x][1]] + 1;
}
inline void rotate(int x) {
int y = fa[x];
if (y == ch[fa[y]][0]) {
ch[fa[y]][0] = x;
}
else {
ch[fa[y]][1] = x;
}
fa[x] = fa[y];
int dir = x == ch[y][1];
ch[y][dir] = ch[x][dir ^ 1];
fa[ch[x][dir ^ 1]] = y;
ch[x][dir ^ 1] = y;
fa[y] = x;
pushup(y);
pushup(x);
}
inline void splay(int x, int rt) {
int p;
top = 0;
for (int i = x; i != rt; i = fa[i]) {
stk[top++] = i;
}
for (int i = top - 1; ~i; --i) {
pushdown(stk[i]);
}
while (fa[x] != rt) {
p = fa[x];
if (fa
 == rt) {
rotate(x);
}
else {
if ((p == ch[fa[p]][1]) ^ (x == ch[p][1])) {
rotate(x);
}
else {
rotate(p);
}
rotate(x);
}
}
if (!rt) {
root = x;
}
}
inline int kth(int k) {
int x = root;
pushdown(x);
while (k != siz[ch[x][0]] + 1) {
if (k <= siz[ch[x][0]]) {
x = ch[x][0];
}
else {
k -= siz[ch[x][0]] + 1;
x = ch[x][1];
}
pushdown(x);
}
return x;
}
int make_tree(int left, int right) {
if (left > right) {
return 0;
}
int rt = (left + right) >> 1;
ch[rt][0] = make_tree(left, rt - 1);
fa[ch[rt][0]] = rt;
ch[rt][1] = make_tree(rt + 1, right);
fa[ch[rt][1]] = rt;
pushup(rt);
return rt;
}
void print(int r) {
if (!r) {
return;
}
pushdown(r);
print(ch[r][0]);
if (r != 1 && r != n + 2) {
printf("%d ", r - 1);
}
print(ch[r][1]);
}

int main(void) {
//freopen("in.txt", "r", stdin);
scanf("%d%d", &n, &m);
root = make_tree(1, n + 2);
while (m--) {
scanf("%d%d", &t1, &t2);
++t1;
++t2;
t1 = kth(t1 - 1);
t2 = kth(t2 + 1);
splay(t1, 0);
splay(t2, root);
rev[ch[ch[root][1]][0]] ^= 1;
}
print(root);
return 0;
}