原题链接：http://www.tyvj.cn/p/1729
这道题以前用c语言写的splay tree水过了。。
现在接触了c++重写一遍。。。
只涉及区间翻转，由于没有删除操作故不带垃圾回收，具体如下：
1 #include<cstdio> 2 #include<cstdlib> 3 #include<iostream> 4 #include<algorithm> 5 const int MAX_N = 100010; 6 struct Node{ 7 int v, s, rev; 8 Node *pre, *ch[2]; 9 inline void set(int _v = 0, int _s = 0, Node *p = NULL){ 10 v = _v, s = _s, rev = 0; 11 pre = ch[0] = ch[1] = p; 12 } 13 inline void push_up(){ 14 s = ch[0]->s + ch[1]->s + 1; 15 } 16 inline void update(){ 17 Node *t = ch[0]; 18 rev ^= 1; 19 t = ch[0]; 20 ch[0] = ch[1]; 21 ch[1] = t; 22 } 23 inline void push_down(){ 24 if (rev != 0){ 25 rev ^= 1; 26 ch[0]->update(); 27 ch[1]->update(); 28 } 29 } 30 }; 31 struct SplayTree{ 32 Node stack[MAX_N]; 33 Node *tail, *root, *null; 34 inline Node *newNode(int v){ 35 Node *p = tail++; 36 p->set(v, 1, null); 37 return p; 38 } 39 void initialize(int l, int r){ 40 tail = &stack[0]; 41 null = tail++; 42 null->set(-1); 43 root = newNode(-1); 44 root->ch[1] = newNode(-1); 45 root->ch[1]->pre = root; 46 Node *x = built(l, r); 47 root->ch[1]->ch[0] = x; 48 x->pre = root->ch[1]; 49 root->ch[1]->push_up(); 50 root->push_up(); 51 } 52 inline void rotate(Node *x, int c){ 53 Node *y = x->pre; 54 y->push_down(), x->push_down(); 55 y->ch[!c] = x->ch[c]; 56 x->pre = y->pre; 57 if (x->ch[c] != null) x->ch[c]->pre = y; 58 if (y->pre != null) y->pre->ch[y->pre->ch[0] != y] = x; 59 x->ch[c] = y; 60 y->pre = x; 61 y->push_up(); 62 if (y == root) root = x; 63 } 64 void splay(Node *x, Node *f){ 65 if (x == root) return; 66 for (; x->pre != f; x->push_down()){ 67 if (x->pre->pre == f){ 68 rotate(x, x->pre->ch[0] == x); 69 } else { 70 Node *y = x->pre, *z = y->pre; 71 if (z->ch[0] == y){ 72 if (y->ch[0] == x) 73 rotate(y, 1), rotate(x, 1); 74 else rotate(x, 0), rotate(x, 1); 75 } else { 76 if (y->ch[1] == x) 77 rotate(y, 0), rotate(x, 0); 78 else rotate(x, 1), rotate(x, 0); 79 } 80 } 81 } 82 x->push_up(); 83 } 84 Node *built(int l, int r){ 85 Node *p = null; 86 if (l > r) return null; 87 int mid = (l + r) >> 1; 88 p = newNode(mid); 89 p->ch[0] = built(l, mid - 1); 90 if (p->ch[0] != null) p->ch[0]->pre = p; 91 p->ch[1] = built(mid + 1, r); 92 if (p->ch[1] != null) p->ch[1]->pre = p; 93 p->push_up(); 94 return p; 95 } 96 Node *select(Node *x, int k){ 97 int t = 0; 98 Node *ret = x; 99 for (;;){ 100 ret->push_down(); 101 t = ret->ch[0]->s; 102 if (t == k) break; 103 if (k < t) ret = ret->ch[0]; 104 else k -= t + 1, ret = ret->ch[1]; 105 } 106 return ret; 107 } 108 void travel(Node *x){ 109 if (x != null){ 110 x->push_down(); 111 travel(x->ch[0]); 112 printf("%d ", x->v); 113 travel(x->ch[1]); 114 } 115 } 116 Node *get_range(int l, int r){ 117 splay(select(root, l - 1), null); 118 splay(select(root, r + 1), root); 119 return root->ch[1]->ch[0]; 120 } 121 void reverse(int l, int r){ 122 Node *ret = get_range(l, r); 123 ret->update(); 124 } 125 void print(int n){ 126 Node *ret = get_range(1, n); 127 travel(ret); 128 } 129 }Splay; 130 int main(){ 131 #ifdef LOCAL 132 freopen("in.txt", "r", stdin); 133 freopen("out.txt", "w+", stdout); 134 #endif 135 int n, m, a, b; 136 while (~scanf("%d %d", &n, &m)){ 137 Splay.initialize(1, n); 138 while (m--){ 139 scanf("%d %d", &a, &b); 140 Splay.reverse(a, b); 141 } 142 Splay.print(n); 143 } 144 return 0; 145 }