fhq：我们有一个新的Treap，支持splay的一切操作你怕不怕。。。
memphis：我们讲的更详细一点好了
1 /************************************************************** 2 Problem: 3223 3 User: rausen 4 Language: C++ 5 Result: Accepted 6 Time:2320 ms 7 Memory:3148 kb 8 ****************************************************************/ 9 10 #include <cstdio> 11 #include <algorithm> 12 13 using namespace std; 14 15 struct node { 16 node *son[2]; 17 int pri, rev, sz, key; 18 } *null, *root, mempool[100005], *cnt_treap = mempool; 19 20 int n; 21 22 inline int read() { 23 int x = 0; 24 char ch = getchar(); 25 while (ch < '0' || '9' < ch) 26 ch = getchar(); 27 while ('0' <= ch && ch <= '9') { 28 x = x * 10 + ch - '0'; 29 ch = getchar(); 30 } 31 return x; 32 } 33 34 inline int rnd() { 35 static int random = 233333; 36 return random += random << 2 | 1; 37 } 38 39 #define Ls p -> son[0] 40 #define Rs p -> son[1] 41 #define Sz p -> sz 42 #define Rev p -> rev 43 inline void reverse_node(node *p) { 44 if (p == null) return; 45 Rev ^= 1; 46 swap(Ls, Rs); 47 } 48 49 inline void push_down(node *p) { 50 if (Rev) { 51 Rev = 0; 52 reverse_node(Ls), reverse_node(Rs); 53 } 54 } 55 56 inline node *update(node *p) { 57 Sz = Ls -> sz + Rs -> sz + 1; 58 return p; 59 } 60 61 node *new_node(int x) { 62 ++cnt_treap; 63 cnt_treap -> sz = 1, cnt_treap -> rev = 0; 64 cnt_treap -> key = x, cnt_treap -> pri = rnd(); 65 cnt_treap -> son[0] = cnt_treap -> son[1] = null; 66 return cnt_treap; 67 } 68 69 node *merge(node *p, node *q) { 70 if (p == null) return update(q); 71 if (q == null) return update(p); 72 if (p -> pri < q -> pri) { 73 push_down(p); 74 p -> son[1] = merge(p -> son[1], q); 75 return update(p); 76 } else { 77 push_down(q); 78 q -> son[0] = merge(p, q -> son[0]); 79 return update(q); 80 } 81 } 82 83 void split(node *p, node *&q, node *&r, int x) { 84 if (p == null) { 85 q = null, r = null; 86 return; 87 } 88 push_down(p); 89 if (Ls -> sz >= x) { 90 split(Ls, q, r, x); 91 Ls = null; 92 update(p); 93 r = merge(r, p); 94 } else { 95 split(Rs, q, r, x - Ls -> sz - 1); 96 Rs = null; 97 push_down(p); 98 q = merge(p, q); 99 } 100 } 101 102 void reverse(int x, int y) { 103 node *p, *q, *r, *s; 104 split(root, p, q, x - 1); 105 split(q, r, s, y - x + 1); 106 reverse_node(r); 107 root = merge(p, merge(r, s)); 108 update(root); 109 } 110 111 void print(node *p) { 112 if (p == null) return; 113 push_down(p); 114 print(Ls); 115 printf("%d ", p -> key); 116 print(Rs); 117 } 118 #undef Ls 119 #undef Rs 120 #undef Sz 121 #undef Rev 122 123 int main() { 124 int Q, i, x, y; 125 n = read(), Q = read(); 126 null = cnt_treap; 127 null -> son[0] = null -> son[1] = null, null -> sz = 0; 128 root = null; 129 for (i = 1; i <= n; ++i) 130 root = merge(root, new_node(i)); 131 while (Q--) { 132 x = read(), y = read(); 133 if (x > y) swap(x, y); 134 reverse(x, y); 135 } 136 print(root); 137 return 0; 138 }
(p.s. 话说这程序又难看速度又捉鸡，下次认真学习了再写。。。)