原题链接：http://acm.hdu.edu.cn/showproblem.php?pid=4217
可用线段树写，效率要高点。
这道题以前用c语言写的treap水过了。。
现在接触了c++重写一遍。。。
不带重复元素的插入删除第k大带垃圾回收，具体如下：
1 #include<cstdio> 2 #include<cstdlib> 3 #include<iostream> 4 #include<algorithm> 5 typedef long long ll; 6 const int MAX_N = 300100; 7 struct Node{ 8 int v, s, fix; 9 Node *ch[2]; 10 inline void 11 set(int _fix, int _v = 0, int _s = 0, Node *p = NULL){ 12 fix = _fix, v = _v, s = _s; 13 ch[0] = ch[1] = p; 14 } 15 inline void push_up(){ 16 s = ch[0]->s + ch[1]->s + 1; 17 } 18 }; 19 int run(){ 20 static int x = 184082857; 21 x += (x << 2) | 1; 22 return x; 23 } 24 struct Treap{ 25 Node *tail, *null, *root; 26 Node stack[MAX_N]; 27 int top; 28 Node *store[MAX_N]; 29 void init(){ 30 tail = &stack[0]; 31 null = tail++; 32 null->set(0x7fffffff); 33 root = null; 34 top = 0; 35 } 36 inline Node *newNode(int v){ 37 Node *p = null; 38 if (top) p = store[--top]; 39 else p = tail++; 40 p->set(run(), v, 1, null); 41 return p; 42 } 43 inline void rotate(Node* &x, int d){ 44 Node *k = x->ch[!d]; 45 x->ch[!d] = k->ch[d]; 46 k->ch[d] = x; 47 k->s = x->s; 48 x->push_up(); 49 x = k; 50 } 51 inline void insert(Node* &x, int v){ 52 if (x == null){ 53 x = newNode(v); 54 return; 55 } else { 56 int d = v > x->v; 57 insert(x->ch[d], v); 58 if (x->ch[d]->fix < x->fix) rotate(x, !d); 59 x->push_up(); 60 } 61 } 62 inline void del(Node* &x, int v){ 63 if (x == null) return; 64 x->s--; 65 if (x->v == v){ 66 if (x->ch[0] == null || x->ch[1] == null){ 67 store[top++] = x; 68 x = x->ch[0] == null ? x->ch[1] : x->ch[0]; 69 } else { 70 int d = x->ch[0]->fix < x->ch[1]->fix; 71 rotate(x, !d); 72 del(x->ch[!d], v); 73 } 74 } else { 75 del(x->ch[v>x->v], v); 76 } 77 if (x != null) x->push_up(); 78 } 79 inline int find_kth(Node *x, int k){ 80 int t = 0; 81 for (;;){ 82 t = x->ch[0]->s; 83 if (k == t + 1) break; 84 else if (k < t + 1) x = x->ch[0]; 85 else k -= t + 1, x = x->ch[1]; 86 } 87 return x->v; 88 } 89 inline void insert(int v){ 90 insert(root, v); 91 } 92 inline void del(int v){ 93 del(root, v); 94 } 95 inline int find_kth(int k){ 96 return find_kth(root, k); 97 } 98 }treap; 99 int main(){ 100 #ifdef LOCAL 101 freopen("in.txt", "r", stdin); 102 freopen("out.txt", "w+", stdout); 103 #endif 104 ll ans; 105 int t, n, m, k, tmp, c = 1; 106 scanf("%d", &t); 107 while (t--){ 108 treap.init(), ans = 0; 109 scanf("%d %d", &n, &m); 110 for (int i = 1; i <= n; i++) treap.insert(i); 111 while (m--){ 112 scanf("%d", &k); 113 ans += tmp = treap.find_kth(k); 114 treap.del(tmp); 115 } 116 printf("Case %d: %lld ", c++, ans); 117 } 118 return 0; 119 }