如题，是一个模板。。。
Splay：
1 #include <algorithm>
2 #include <iostream>
3 #include <cstring>
4 #include <cstdio>
5 #include <cctype>
6
7 inline void read(int & x)
8 {
9 x = 0;
10 int k = 1;
11 char c = getchar();
12 while (!isdigit(c))
13 if (c == '-') c = getchar(), k = -1;
14 else c = getchar();
15 while (isdigit(c))
16 x = (x << 1) + (x << 3) + (c ^ 48),
17 c = getchar();
18 x *= k;
19 }
20
21 const int MAXN = 101015;
22 int n, m, x, y;
23
24 int a[101010];
25
26 struct SplayHello
27 {
28 int rt = 0, tot = 0;
29 int cnt[MAXN];
30 int siz[MAXN];
31 int tag[MAXN];
32 int val[MAXN];
33 int faz[MAXN];
34 int son[MAXN][2];
35
36 int Getson(int u)
37 {
38 return son[faz[u]][1] == u;
39 }
40
41 void Update(int u)
42 {
43 siz[u] = siz[son[u][0]] + siz[son[u][1]] + cnt[u];
44 }
45
46 void Pushdown(int u) //ok
47 {
48 if (!tag[u] || !u) return;
49 if (son[u][0]) tag[son[u][0]] ^= 1;
50 if (son[u][1]) tag[son[u][1]] ^= 1;
51 son[u][0] ^= son[u][1],
52 son[u][1] ^= son[u][0],
53 son[u][0] ^= son[u][1];
54 tag[u] = 0;
55 }
56
57 int Build(int dad, int l, int r) //ok
58 {
59 if (l > r) return 0;
60 int mid = (l + r) >> 1;
61 int now = ++tot;
62 tag[now] = 0;
63 faz[now] = dad;
64 val[now] = a[mid];
65 cnt[now] = siz[now] = 1;
66 son[now][0] = Build(now, l, mid - 1);
67 son[now][1] = Build(now, mid + 1, r);
68 //²»ÄÜÓÃtotµ±¸¸Ç×£¬»á¸Ä±ä
69 Update(now);
70 return now;
71 }
72
73 void Rotate(int u) //ok
74 {
75 int y = faz[u], z = faz[y], ch = Getson(u);
76 Pushdown(y), Pushdown(u);
77 int b = son[u][ch ^ 1];
78 int d = Getson(y);
79 son[u][ch ^ 1] = y, son[y][ch] = b;
80 faz[y] = u, faz[b] = y, faz[u] = z;
81 if (z) son[z][d] = u;
82 Update(y), Update(u);
83 }
84
85 void Splay(int u, int tar) //ok
86 {
87 while (faz[u] != tar)
88 {
89 if (faz[faz[u]] != tar)
90 if (Getson(u) == Getson(faz[u])) Rotate(faz[u]);
91 else Rotate(u);
92 Rotate(u);
93 }
94 if (!tar) rt = u;
95 }
96
97 int GetKth(int k)
98 {
99 int now = rt;
100 while (true)
101 {
102 Pushdown(now);
103 if (siz[son[now][0]] >= k) now = son[now][0];
104 else if (siz[son[now][0]] + cnt[now] >= k) return now;
105 else k -= siz[son[now][0]] + cnt[now], now = son[now][1];
106 }
107 }
108
109 void Rever(int l, int r)
110 {
111 int L = GetKth(l - 1);
112 int R = GetKth(r + 2);
113 Splay(L, 0); Splay(R, L);
114 tag[son[son[rt][1]][0]] ^= 1;
115 Update(L), Update(R), Update(son[R][0]);
116 }
117
118 void print(int u)
119 {
120 Pushdown(u);
121 if (son[u][0]) print(son[u][0]);
122 if (val[u] != -2147483600 && val[u] != 2147483600)
123 printf("%d ", val[u]);
124 if (son[u][1]) print(son[u][1]);
125 }
126
127 void BuildT(int l, int r)
128 {
129 rt = Build(0, l, r);
130 }
131
132 void printT()
133 {
134 print(rt);
135 }
136 }splay;
137
138 signed main()
139 {
140 read(n), read(m);
141 for (int i = 1; i <= n; ++i) a[i] = i;
142 a[n + 1] = 2147483600;
143 a[0] = -2147483600;
144 splay.BuildT(0, n + 1);
145 for (int i = 1; i <= m; ++i)
146 {
147 read(x), read(y);
148 splay.Rever(x, y);
149 }
150 splay.printT();
151 return 0;
152 }
FHQ：：
1 #include <algorithm>
2 #include <iostream>
3 #include <cstring>
4 #include <cstdio>
5 #include <cctype>
6
7 inline void read(int & x)
8 {
9 x = 0;
10 int k = 1;
11 char c = getchar();
12 while (!isdigit(c))
13 if (c == '-') c = getchar(), k = -1;
14 else c = getchar();
15 while (isdigit(c))
16 x = (x << 1) + (x << 3) + (c ^ 48),
17 c = getchar();
18 x *= k;
19 }
20
21 const int MAXN = 1e5 + 999;
22 int seed = 1024, n, m, l, r, rt = 0, tot = 0, rnd[MAXN], tag[MAXN], val[MAXN], siz[MAXN], son[MAXN][2];
23
24 inline int Rand(void)
25 {
26 return seed = (int)seed * 462711LL % 2147483647;
27 }
28
29 inline int New(int x)
30 {
31 ++tot;
32 siz[tot] = 1;
33 val[tot] = x;
34 rnd[tot] = Rand();
35 tag[tot] = son[tot][1] = son[tot][0] = 0;
36 return tot;
37 }
38
39 inline void Swap(int &a, int &b)
40 {
41 a ^= b, b ^= a, a ^= b;
42 }
43
44 inline void Pushup(int u)
45 {
46 siz[u] = siz[son[u][0]] + siz[son[u][1]] + 1;
47 }
48
49 inline void Pushdown(int u)
50 {
51 if (!tag[u]) return;
52 tag[son[u][0]] ^= 1;
53 tag[son[u][1]] ^= 1;
54 Swap(son[u][0], son[u][1]);
55 tag[u] = 0;
56 }
57
58 inline void Split(int u, int k, int &a, int &b)
59 {
60 if (!u) { a = b = 0; return; }
61 Pushdown(u);
62 if (k <= siz[son[u][0]]) b = u, Split(son[u][0], k, a, son[b][0]);
63 else a = u, Split(son[u][1], k - siz[son[u][0]] - 1, son[a][1], b);
64 Pushup(u);
65 }
66
67 inline void Merge(int & u, int a, int b)
68 {
69 if (!a || !b) { u = a | b; return; }
70 if (rnd[a] < rnd[b]) u = a, Pushdown(a), Merge(son[u][1], son[a][1], b), Pushup(a);
71 else u = b, Pushdown(b), Merge(son[u][0], a, son[b][0]), Pushup(b);
72 }
73
74 inline void Insert(int x)
75 {
76 int u = New(x);
77 Merge(rt, rt, u);
78 }
79
80 inline void Print(int u)
81 {
82 if (!u) return;
83 Pushdown(u);
84 Print(son[u][0]);
85 printf("%d ", val[u]);
86 Print(son[u][1]);
87 }
88
89 int a, b, c;
90
91 signed main()
92 {
93 read(n), read(m);
94 for (int i = 1; i <= n; ++i) Insert(i);
95 for (int i = 1; i <= m; ++i)
96 {
97 a = b = c = 0;
98 read(l), read(r);
99 Split(rt, r, a, b);
100 Split(a, l - 1, a, c);
101 tag[c] ^= 1;
102 Merge(a, a, c);
103 Merge(rt, a, b);
104 }
105 Print(rt);
106 return 0;
107 }
来源：https://www.cnblogs.com/yanyiming10243247/p/10057820.html