二元搜尋樹(BST)的簡單定義:
這樣的資料結構可以維護一個集合的以下操作:
該資料結構最優情況下單次查詢僅需 \(\Theta(\log_2{n})\) 的時間複雜度,但通過構造輸入可以使二元搜尋樹退化為鏈,達到 \(\Theta(n)\) 的時間複雜度。
所以我們要讓這棵二元搜尋樹儘量平衡(深度接近 \(\log_2{n}\))。
於是就誕生了平衡樹。
可以發現左旋/右旋後樹的形態發生變化,但仍然滿足二元搜尋樹的性質。
Splay 的核心操作,即把一個點提到根。
分三種情況:
為什麼要這麼轉呢?因為直接單旋上去無法保證複雜度,隨隨便便就能卡掉,而雙旋的時間複雜度可以用勢能分析法進行分析。
根據 BST 的性質找到一個地方插入新點,然後把它旋上去。
假設當前到了點 \(p\):
找到 \(x\) 提到根,左子樹的大小加 \(1\) 就是答案。
把 \(x\) 提到根後,在左子樹裡一路往右走。
把 \(x\) 提到根後,在右子樹裡一路往左走。
最麻煩的一個。
首先我們把 \(x\) 提到根
const ll N = 2e5 + 10, INF = 1ll << 40;
namespace Splay {
class TreePoint {
public:
ll val, cnt, sz;
ll fa, son[2];
inline void New (ll num) { val = num, cnt = sz = 1, fa = son[0] = son[1] = 0; return; }
inline void Clear () { val = cnt = sz = fa = son[0] = son[1] = 0; return; }
};
class splay {
public:
TreePoint tr[N];
ll tot = 0, rt = 0;
#define va(p) tr[p].val
#define cn(p) tr[p].cnt
#define sz(p) tr[p].sz
#define fa(p) tr[p].fa
#define so(p, lr) tr[p].son[lr]
inline void PushUp (ll p) { sz (p) = sz (so (p, 0)) + sz (so (p, 1)) + cn (p); return; } // Update the size.
inline bool Get (ll p) { return p == so (fa (p), 1); } // Left son(0) or right son(1)?
inline ll NewPoint (ll num) { tr[++tot].New (num); return tot; } // Build a new Point.
inline void Rotate (ll p) {
ll q = fa (p), r = fa (q), sd = Get (p);
so (q, sd) = so (p, sd ^ 1);
if (so (p, sd ^ 1)) fa (so (p, sd ^ 1)) = q;
so (p, sd ^ 1) = q, fa (q) = p, fa (p) = r;
if (r) so (r, q == so (r, 1)) = p;
PushUp (q), PushUp (p);
return;
} // Zig or zag.
inline void Splay (ll p) {
for (ll q = fa (p); q = fa (p), q; Rotate (p))
if (fa (q)) Rotate (Get (p) == Get (q) ? q : p);
rt = p;
return;
} // Splay's core operations!
inline void Out () {
_for (i, 1, tot) {
printf ("%lld : val=%lld cnt=%lld sz=%lld fa=%lld %lld %lld\n", i, va (i), cn (i), sz (i), fa (i), so (i, 0), so (i, 1));
}
puts ("");
return;
} // For debug.
inline void Insert (ll x) {
if (!rt) rt = NewPoint (x), PushUp (rt);
else {
ll p = rt;
while (1) {
ll sd = (bool)(va (p) < x);
if (va (p) == x) {
++cn (p);
PushUp (p), PushUp (fa (p));
break;
}
else if (so (p, sd)) p = so (p, sd);
else {
so (p, sd) = NewPoint (x);
fa (so (p, sd)) = p, p = so (p, sd);
PushUp (p), PushUp (fa (p));
break;
}
}
Splay (p);
}
return;
} // Insert a number x.
inline ll GetRank (ll x) {
ll p = rt, cnt = 1;
while (p) {
if (va (p) <= x) {
cnt += sz (so (p, 0));
if (va (p) == x) break;
cnt += cn (p);
p = so (p, 1);
}
else p = so (p, 0);
}
Splay (p);
return cnt;
} // Get x's rank.
inline ll GetKth (ll x) {
ll p = rt;
while (p) {
if (sz (so (p, 0)) < x) {
x -= sz (so (p, 0));
if (cn (p) >= x) break;
x -= cn (p);
p = so (p, 1);
}
else p = so (p, 0);
}
Splay (p);
return va (p);
} // Get k-th number.
inline ll RealPre () {
ll p = so (rt, 0);
if (p) {
while (so (p, 1)) p = so (p, 1);
Splay (p);
}
return p;
}
inline void Delete (ll x) {
GetRank (x);
ll sd = (bool)(so (rt, 1));
if (cn (rt) > 1) --cn (rt), PushUp (rt);
else if (!so (rt, 0) && !so (rt, 1)) tr[rt].Clear (), rt = 0;
else if (so (rt, 0) && so (rt, 1)) {
ll p = rt, q = RealPre ();
fa (so (p, 1)) = q;
so (q, 1) = so (p, 1);
tr[p].Clear ();
PushUp (rt);
}
else {
ll q = so (rt, sd);
tr[rt].Clear ();
fa (rt = q) = 0;
}
return;
} // Delete a number x.
inline ll Pre (ll x) {
Insert (x);
ll ans = va (RealPre ());
Delete (x);
return ans;
} // Get x's pre.
inline ll Next (ll x) {
Insert (x);
ll p = so (rt, 1), ans = 0;
if (p) {
while (so (p, 0)) p = so (p, 0);
Splay (p);
}
ans = va (rt);
Delete (x);
return ans;
} // Get x's next.
#undef va
#undef cn
#undef sz
#undef fa
#undef so
};
}
很暴力的一個東西。
定義一個平衡因子 \(\alpha\)(最好選 \(0.7\sim0.8\)),插入/刪除一個節點的時候檢查是否存在一個節點的子樹的大小乘上 \(\alpha\) 小於左/右兒子樹的大小,如果有則把這棵子樹直接拍平重構。
其他操作和普通 BST 一樣。
namespace ScapeGoatTree {
const ldb alpha = 0.75;
const ll N = 1e5 + 10;
class TreePoint {
public:
ll val, cnt, sz, cp, del;
ll fa, son[2];
};
class SGT {
private:
ll tot = 0, rt = 0, dp[N], cd = 0;
TreePoint tr[N];
vec tmp, c;
#define va(p) tr[p].val
#define cn(p) tr[p].cnt
#define sz(p) tr[p].sz
#define de(p) tr[p].del
#define cp(p) tr[p].cp
#define fa(p) tr[p].fa
#define so(p, lr) tr[p].son[lr]
inline ll NewP (ll num) {
ll p = cd ? dp[cd--] : ++tot;
va (p) = num;
cn (p) = sz (p) = 1;
cp (p) = fa (p) = so (p, 0) = so (p, 1) = de (p) = 0;
return p;
}
inline void DelP (ll p) {
va (p) = cn (p) = sz (p) = cp (p) = fa (p) = so (p, 0) = so (p, 1) = de (p) = 0;
dp[++cd] = p;
return;
}
inline void PushUp (ll p) {
sz (p) = (de (p) ? 0 : cn (p)) + sz (so (p, 0)) + sz (so (p, 1));
cp (p) = 1 + cp (so (p, 0)) + cp (so (p, 1));
return;
}
public:
inline void Clap (ll p) {
if (so (p, 0)) Clap (so (p, 0));
if (!de (p)) tmp.push_back (va (p)), c.push_back (cn (p));
if (so (p, 1)) Clap (so (p, 1));
DelP (p);
return;
}
inline ll PullUp (ll l, ll r, ll fat) {
if (l > r) return 0;
bdmd;
ll p = NewP (tmp[mid]);
cn (p) = c[mid], fa (p) = fat;
if (l < mid) so (p, 0) = PullUp (l, mid - 1, p);
if (mid < r) so (p, 1) = PullUp (mid + 1, r, p);
PushUp (p);
return p;
}
inline void ReBuild (ll p) {
ll q = fa (p);
tmp.clear (), c.clear ();
Clap (p);
if (!q) rt = PullUp (0, tmp.size () - 1, q);
else so (q, p == so (q, 1)) = PullUp (0, tmp.size () - 1, q);
return;
}
inline bool Bad (ll p) {
return cp (so (p, 0)) > cp (p) * alpha || cp (so (p, 1)) > cp (p) * alpha;
}
inline void Check (ll p) {
ll q = 0;
while (p) {
if (Bad (p)) q = p;
rt = p;
PushUp (p);
p = fa (p);
}
if (q) ReBuild (q);
return;
}
inline void Insert (ll num) {
ll p = rt;
if (!rt) {
rt = NewP (num);
return;
}
while (1) {
if (va (p) == num) {
++cn (p);
if (de (p)) de (p) = 0;
Check (p);
return;
}
ll sd = num > va (p);
if (so (p, sd)) p = so (p, sd);
else {
so (p, sd) = NewP (num);
fa (so (p, sd)) = p;
Check (p);
return;
}
}
return;
}
inline void Delete (ll num) {
ll p = rt;
while (p) {
if (va (p) == num) {
--cn (p);
if (cn (p) < 1) {
cn (p) = 0;
de (p) = 1;
}
Check (p);
return;
}
ll sd = num > va (p);
p = so (p, sd);
}
return;
}
inline ll GetRank (ll num) {
ll p = rt, rk = 1;
while (p) {
if (va (p) > num) {
p = so (p, 0);
continue;
}
rk += sz (so (p, 0));
if (num == va (p)) break;
rk += cn (p);
p = so (p, 1);
}
return rk;
}
inline ll GetKth (ll k) {
ll p = rt;
while (p) {
if (sz (so (p, 0)) >= k) {
p = so (p, 0);
continue;
}
k -= sz (so (p, 0));
if (k <= cn (p)) break;
k -= cn (p);
p = so (p, 1);
}
return va (p);
}
inline ll Pre (ll num) { return GetKth (GetRank (num) - 1); }
inline ll Nxt (ll num) { return GetKth (GetRank (num + 1)); }
#undef va
#undef cn
#undef sz
#undef de
#undef cp
#undef fa
#undef so
};
}
每個節點還要存一個隨機權值,使得整棵樹不僅對於原權值來說是一棵 BST,對於隨機權值來說還是一個堆,在隨機狀態下一棵 Treap 是比較 \(\log_2n\) 層的。當然不排除你臉太黑導致 Treap 退化成鏈的極小可能。
那麼插入的時候,如果新節點不滿足堆的性質了,需要往上旋轉。刪除的時候直接旋到葉子結點刪掉,或者只剩一個兒子的時候直接讓兒子代替自己。
其他操作和普通 BST 一樣。
namespace TREAP {
class TreePoint {
public:
ll val, rk, sz, cnt;
ll son[2];
inline void NewP (ll x) { val = x, rk = rand (), cnt = sz = 1, son[0] = son[1] = 0;return; }
};
class Treap {
public:
TreePoint tr[N];
ll tot = 0, rt = 0;
#define va(p) tr[p].val
#define rk(p) tr[p].rk
#define sz(p) tr[p].sz
#define cn(p) tr[p].cnt
#define so(p, lr) tr[p].son[lr]
inline void PushUp (ll p) { sz (p) = cn (p) + sz (so (p, 0)) + sz (so (p, 1)); return; }
inline ll NewP (ll num) { tr[++tot].NewP (num); return tot; }
inline void DelP (ll p) { va (p) = rk (p) = sz (p) = cn (p) = so (p, 0) = so (p, 1) = 0;return; }
inline void Rotate (ll& p, ll sd) {
ll q = so (p, sd ^ 1);
so (p, sd ^ 1) = so (q, sd);
so (q, sd) = p, p = q;
PushUp (so (q, sd)), PushUp (q);
return;
}
void Insert (ll& p, ll x) {
if (!p) {
p = NewP (x);
return;
}
if (va (p) == x) ++cn (p);
else {
bool sd = (va (p) < x);
Insert (so (p, sd), x);
if (rk (so (p, sd)) > rk (p)) Rotate (p, sd ^ 1);
}
PushUp (p);
return;
}
void Delete (ll& p, ll x) {
if (!p) return;
if (va (p) == x) {
if (cn (p) == 1) {
if (!so (p, 0) && !so (p, 1)) DelP (p), p = 0;
else if (!so (p, 0) || !so (p, 1)) p = so (p, 0) + so (p, 1);
else {
ll sd = (rk (so (p, 1)) < rk (so (p, 0)));
Rotate (p, sd), Delete (so (p, sd), x);
}
}
else --cn (p);
}
else Delete (so (p, (x > va (p))), x);
PushUp (p);
return;
}
ll GetRank (ll p, ll x) {
if (!p) return 1;
if (va (p) == x) return 1 + sz (so (p, 0));
if (va (p) < x) return GetRank (so (p, 1), x) + sz (so (p, 0)) + cn (p);
return GetRank (so (p, 0), x);
}
ll GetKth (ll p, ll x) {
if (!p) return 0;
if (x <= sz (so (p, 0))) return GetKth (so (p, 0), x);
x -= sz (so (p, 0));
if (x <= cn (p)) return va (p);
x -= cn (p);
return GetKth (so (p, 1), x);
}
ll Pre (ll x) { return GetKth (rt, GetRank (rt, x) - 1); }
ll Next (ll x) { return GetKth (rt, GetRank (rt, x + 1)); }
#undef va
#undef rk
#undef sz
#undef cn
#undef so
};
}
FHQ_Treap 依舊滿足 Treap 的性質,但是操作方式很神奇!
FHQ_Treap 也被稱為無旋 Treap,因為它的所有操作都沒有噁心的旋轉,只有分裂和合並兩個基礎操作!
分裂有兩種方法:按權值裂和按排名裂。一般來說,只當平衡樹的時候通常按權值裂,維護序列的時候按排名裂。具體怎麼裂見程式碼和例題。
合併的時候要保證第一棵樹的所有權值都比第二棵樹小,注意合的過程中要保證 Treap 的性質。
為了方便寫我沒有寫副本數。
然後就是六個操作了:
插入
按 \(x\) 裂成 \(a,b\) 兩棵樹,然後按 \(a,x,b\) 的順序合起來
刪除
這絕對是刪除操作最簡單的平衡樹了!先按 \(x\) 裂成 \(a,b\) 兩棵樹,再把 \(a\) 按 \(x-1\) 裂成 \(a,c\) 兩棵樹,此時
查詢排名為 \(k\) 的數
和普通 BST 一樣。
查詢 \(x\) 的排名
按 \(x-1\) 裂成 \(a,b\) 兩棵樹,\(a\) 的大小加一就是答案
查詢 \(x\) 的前驅
按 \(x-1\) 裂成 \(a,b\) 兩棵樹,\(a\) 裡的最大值
查詢 \(x\) 的後繼
按 \(x-1\) 裂成 \(a,b\) 兩棵樹,\(b\) 裡的最小值
namespace FHQ_TREAP {
class TreeNode {
public:
ll val, rk, sz, son[2];
inline void Add (ll num) { val = num, rk = rand (), sz = 1, son[0] = son[1] = 0; return; }
};
class FHQTreap {
private:
TreeNode tr[N];
ll tot = 0, rt = 0, a, b, c;
#define va(p) tr[p].val
#define rk(p) tr[p].rk
#define sz(p) tr[p].sz
#define so(p, lr) tr[p].son[lr]
inline ll NewP (ll num) { tr[++tot].Add (num); return tot; }
inline void PushUp (ll p) { sz (p) = 1 + sz (so (p, 0)) + sz (so (p, 1)); return; }
void Split (ll p, ll x, ll& l, ll& r) {
if (!p) l = r = 0;
else {
if (va (p) <= x) l = p, Split (so (p, 1), x, so (p, 1), r);
else r = p, Split (so (p, 0), x, l, so (p, 0));
PushUp (p);
}
return;
}
inline ll Merge (ll l, ll r) {
if (!l || !r) return l + r;
if (rk (l) < rk (r)) {
so (l, 1) = Merge (so (l, 1), r);
PushUp (l);
return l;
}
else {
so (r, 0) = Merge (l, so (r, 0));
PushUp (r);
return r;
}
}
public:
inline void Insert (ll x) {
Split (rt, x, a, b);
rt = Merge (Merge (a, NewP (x)), b);
return;
}
inline void Delete (ll x) {
Split (rt, x, a, b);
Split (a, x - 1, a, c);
rt = Merge (Merge (a, Merge (so (c, 0), so (c, 1))), b);
return;
}
inline ll GetRank (ll x) {
Split (rt, x - 1, a, b);
ll ans = sz (a) + 1;
rt = Merge (a, b);
return ans;
}
inline ll GetKth (ll x) {
ll p = rt;
while (p) {
if (x <= sz (so (p, 0))) p = so (p, 0);
else {
x -= sz (so (p, 0)) + 1;
if (!x) break;
p = so (p, 1);
}
}
return va (p);
}
inline ll Pre (ll x) {
Split (rt, x - 1, a, b);
ll p = a;
while (so (p, 1)) p = so (p, 1);
rt = Merge (a, b);
return va (p);
}
inline ll Next (ll x) {
Split (rt, x, a, b);
ll p = b;
while (so (p, 0)) p = so (p, 0);
rt = Merge (a, b);
return va (p);
}
#undef va
#undef rk
#undef sz
#undef so
};
}
用於維護單點修改和區間第 \(k\) 大,排名,前驅和後繼的查詢。
首先建立一棵線段樹,每個節點單建一棵平衡樹維護這個區間(線段樹的每一層有 \(n\) 個節點,一共 \(\log_2n\) 層,因此只有 \(n\log_2n\) 個節點,不會 TLE/MLE)。
然後是如何維護五個操作:
const ll N = 1e5 + 10, inf = 2147483647;
namespace FHQ_TREAP {
class TreeNode {
public:
ll val, rk, sz, son[2];
inline void Add (ll num) noexcept { val = num, rk = rand (), sz = 1, son[0] = son[1] = 0; return; }
} tr[N << 4];
ll tot = 0, len = 0, free[N << 4];
#define va(p) tr[p].val
#define rk(p) tr[p].rk
#define sz(p) tr[p].sz
#define so(p, lr) tr[p].son[lr]
class FHQTreap {
private:
ll rt = 0, a, b, c;
inline void PushUp (ll p) noexcept { sz (p) = 1 + sz (so (p, 0)) + sz (so (p, 1)); }
inline ll NewP (ll num) noexcept {
ll p = len ? free[len--] : ++tot;
tr[p].Add (num);
return p;
}
inline void DelP (ll p) noexcept {
va (p) = rk (p) = sz (p) = so (p, 0) = so (p, 1) = 0;
free[++len] = p;
return;
}
inline void Split (ll p, ll x, ll& l, ll& r) noexcept {
if (!p) l = r = 0;
else {
if (va (p) <= x) l = p, Split (so (p, 1), x, so (p, 1), r);
else r = p, Split (so (p, 0), x, l, so (p, 0));
PushUp (p);
}
return;
}
inline ll Merge (ll l, ll r) noexcept {
if (!l || !r) return l + r;
if (rk (l) > rk (r)) {
so (l, 1) = Merge (so (l, 1), r);
PushUp (l);
return l;
}
else {
so (r, 0) = Merge (l, so (r, 0));
PushUp (r);
return r;
}
}
public:
inline void Insert (ll x) noexcept {
Split (rt, x, a, b);
rt = Merge (Merge (a, NewP (x)), b);
return;
}
inline void Delete (ll x) noexcept {
Split (rt, x, a, b);
Split (a, x - 1, a, c);
rt = Merge (Merge (a, Merge (so (c, 0), so (c, 1))), b);
DelP (c);
return;
}
inline ll GetRank (ll x) noexcept {
Split (rt, x - 1, a, b);
ll ans = sz (a);
rt = Merge (a, b);
return ans;
}
inline ll Pre (ll x) noexcept {
Split (rt, x - 1, a, b);
ll p = a;
while (so (p, 1)) p = so (p, 1);
rt = Merge (a, b);
return va (p);
}
inline ll Next (ll x) noexcept {
Split (rt, x, a, b);
ll p = b;
while (so (p, 0)) p = so (p, 0);
rt = Merge (a, b);
return va (p);
}
};
#undef va
#undef rk
#undef sz
#undef so
}
namespace SEGMENT_TREE {
class SegmentTree {
private:
FHQ_TREAP::FHQTreap tr[N << 2];
#define ls(p) p << 1, l, mid
#define rs(p) p << 1 | 1, mid + 1, r
public:
inline void Build (ll p, ll l, ll r, ll* a) noexcept {
if (l != r) {
ll mid = md;
Build (ls (p), a);
Build (rs (p), a);
}
tr[p].Insert (inf), tr[p].Insert (-inf);
_for (i, l, r) tr[p].Insert (a[i]);
return;
}
inline void Update (ll p, ll l, ll r, ll x, ll y, ll z) noexcept {
if (r < x || x < l) return;
if (l != r) {
ll mid = md;
Update (ls (p), x, y, z);
Update (rs (p), x, y, z);
}
tr[p].Delete (z), tr[p].Insert (y);
}
inline ll QueryRank (ll p, ll l, ll r, ll le, ll ri, ll x) noexcept {
if (ri < l || r < le) return 0;
ll mid = md;
if (le <= l && r <= ri) return tr[p].GetRank (x) - 1;
else return QueryRank (ls (p), le, ri, x) + QueryRank (rs (p), le, ri, x);
}
inline ll QueryKth (ll le, ll ri, ll x, ll n, ll mx) noexcept {
ll l = 0, r = mx, ans = 0;
while (l <= r) {
ll mid = md;
if (QueryRank (1, 1, n, le, ri, mid) + 1 <= x) ans = mid, l = mid + 1;
else r = mid - 1;
}
return ans;
}
inline ll QueryPre (ll p, ll l, ll r, ll le, ll ri, ll x) noexcept {
if (ri < l || r < le) return -inf;
ll mid = md;
if (le <= l && r <= ri) return tr[p].Pre (x);
else return std::max (QueryPre (ls (p), le, ri, x), QueryPre (rs (p), le, ri, x));
}
inline ll QueryNext (ll p, ll l, ll r, ll le, ll ri, ll x) noexcept {
if (ri < l || r < le) return inf;
ll mid = md;
if (le <= l && r <= ri) return tr[p].Next (x);
else return std::min (QueryNext (ls (p), le, ri, x), QueryNext (rs (p), le, ri, x));
}
};
}
平衡樹不是隻能平衡樹,也可以進行區間操作。
用平衡樹中序遍歷順序不變的性質,維護序列中每個數的前後位置(即把按數值排序變為按下標排序)。
操作時,把需要操作/查詢的區間放在一顆子樹上再直接對子樹進行操作/查詢。
如果操作對子樹的所有點生效,應該給子樹打個標記,旋轉/分裂/合併的時候隨手下傳標記。
使用 Splay:通過對 \(l-1\) 和 \(r+1\) 提根使得區間 \([l, r]\) 在一顆子樹上,然後對這棵子樹進行操作。
使用 FHQ-Treap:把區間 \([l, r]\) 裂出來,然後對這棵子樹進行操作,再合併回去。
平衡樹還支援插入/刪除一個點,所以維護序列的時候還可以在任意位置加入/刪除一個數。
另外,FHQ-Treap 裂開合併的神奇操作還支援對一個區間進行移動。
對需要操作的區間打個翻轉標記,同時交換其左右兒子。
維護一棵子樹的字串的雜湊值,然後就是裸的區間操作了。
不難發現每次插入的數都會比之前插入的數都大,因此插完之後最長上升子序列的長度不會變化。
那麼每個節點維護一個子樹最長上升子序列的長度的最大值,插入時選一個前面的最長的最長上升子序列接上。
把這棵樹轉換成 dfs 序序列,然後對於三個操作:
const ll N = 1e6+ 10;
namespace FHQ_TREAP {
class TreeNode {
public:
ll val, pn, rk, sz, so[2], ta, sum, sp, fa;
inline void Add (ll num, ll tmp) { sum = val = num * tmp, sp = pn = tmp, rk = rand (), sz = 1, so[0] = so[1] = 0; return; }
};
class FHQTreap {
private:
TreeNode tr[N];
ll tot = 0, rt = 0, a, b, c;
#define va(p) tr[p].val
#define ta(p) tr[p].ta
#define rk(p) tr[p].rk
#define sz(p) tr[p].sz
#define pn(p) tr[p].pn
#define su(p) tr[p].sum
#define sp(p) tr[p].sp
#define fa(p) tr[p].fa
#define so(p, lr) tr[p].so[lr]
inline ll NewP (ll num, ll pn) { tr[++tot].Add (num, pn); return tot; }
inline void PushUp (ll p) {
sz (p) = 1 + sz (so (p, 0)) + sz (so (p, 1));
su (p) = va (p) + su (so (p, 0)) + su (so (p, 1));
sp (p) = pn (p) + sp (so (p, 0)) + sp (so (p, 1));
fa (so (p, 0)) = fa (so (p, 1)) = p;
return;
}
inline void Tag (ll p, ll num) {
ta (p) += num;
va (p) += num * pn (p);
su (p) += num * sp (p);
return;
}
inline void PushDown (ll p) {
if (!ta (p)) return;
if (so (p, 0)) Tag (so (p, 0), ta (p));
if (so (p, 1)) Tag (so (p, 1), ta (p));
fa (so (p, 0)) = fa (so (p, 1)) = p;
ta (p) = 0;
return;
}
inline void Split (ll p, ll x, ll& l, ll& r) {
if (!p) l = r = 0;
else {
PushDown (p);
if (sz (so (p, 0)) < x) l = p, Split (so (p, 1), x - sz (so (p, 0)) - 1, so (p, 1), r);
else r = p, Split (so (p, 0), x, l, so (p, 0));
PushUp (p);
}
return;
}
inline ll Merge (ll l, ll r) {
PushDown (l), PushDown (r);
if (!l || !r) return l + r;
if (rk (l) > rk (r)) {
so (l, 1) = Merge (so (l, 1), r);
PushUp (l);
return l;
}
else {
so (r, 0) = Merge (l, so (r, 0));
PushUp (r);
return r;
}
}
inline ll GetRank (ll x) {
ll cnt = sz (so (x, 0)) + 1;
for (ll p = x; fa (p); p = fa (p))
if (so (fa (p), 1) == p) cnt += sz (so (fa (p), 0)) + 1;
return cnt;
}
public:
inline void Insert (ll x, ll p) {
rt = Merge (rt, NewP (x, p));
return;
}
inline void Modify (ll l, ll r, ll x) {
l = GetRank (l), r = GetRank (r);
Split (rt, r, a, b);
Split (a, l - 1, a, c);
Tag (c, x);
rt = Merge (Merge (a, c), b);
return;
}
inline void Move (ll l, ll r, ll x) {
l = GetRank (l), r = GetRank (r), x = GetRank (x);
if (x > r) x -= r - l + 1;
Split (rt, r, a, b);
Split (a, l - 1, a, c);
a = Merge (a, b);
Split (a, x, a, b);
rt = Merge (Merge (a, c), b);
return;
}
inline ll Query (ll x) {
x = GetRank (x);
Split (rt, x, a, b);
ll ans = su (a);
rt = Merge (a, b);
return ans;
}
#undef va
#undef ta
#undef rk
#undef sz
#undef pn
#undef su
#undef sp
#undef fa
#undef so
};
}
namespace SOLVE {
FHQ_TREAP::FHQTreap tr;
ll n, m, fa[N], w[N], cnt;
ll dfn[N], sec[N][2];
std::vector<ll> tu[N];
inline ll rnt () {
ll x = 0, w = 1; char c = getchar ();
while (!isdigit (c)) { if (c == '-') w = -1; c = getchar (); }
while (isdigit (c)) x = (x << 3) + (x << 1) + (c ^ 48), c = getchar ();
return x * w;
}
inline char rch () {
char c = getchar ();
while (c < 'A' || 'Z' < c) c = getchar ();
return c;
}
inline void Dfs (ll x) {
dfn[sec[x][0] = ++cnt] = x;
tr.Insert (w[x], 1);
far (i, tu[x]) Dfs (i);
sec[x][1] = ++cnt;
tr.Insert (w[x], -1);
return;
}
inline void In () {
n = rnt ();
_for (i, 2, n) {
fa[i] = rnt ();
tu[fa[i]].push_back (i);
}
_for (i, 1, n) w[i] = rnt ();
m = rnt ();
Dfs (1);
return;
}
inline void Out () {
while (m--) {
char opt = rch ();
if (opt == 'Q') {
ll d = rnt ();
printf ("%lld\n", tr.Query (sec[d][0]));
}
else if (opt == 'C') {
ll x = rnt (), y = rnt ();
tr.Move (sec[x][0], sec[x][1], sec[y][0]);
}
else {
ll x = rnt (), y = rnt ();
tr.Modify (sec[x][0], sec[x][1], y);
}
}
return;
}
}
本文來自部落格園,作者:Keven-He,轉載請註明原文連結:https://www.cnblogs.com/Keven-He/p/SplayAndTreap.html