原题链接：http://acm.hust.edu.cn/vjudge/problem/viewProblem.action?id=46093
1 #include<algorithm> 2 #include<iostream> 3 #include<cstdlib> 4 #include<cstdio> 5 const int Max_N = 101000; 6 struct Node { 7 int v, s; 8 Node *ch[2]; 9 inline void set(int _v, int _s , Node *p) { 10 ch[0] = ch[1] = p; 11 v = _v, s = _s; 12 } 13 inline void push_up() { 14 s = ch[0]->s + ch[1]->s + 1; 15 } 16 inline int cmp(int x) const { 17 return x > v; 18 } 19 }; 20 struct SizeBalanceTree { 21 Node *tail, *root, *null; 22 Node stack[Max_N]; 23 void init(){ 24 tail = &stack[0]; 25 null = tail++; 26 null->set(0, 0, NULL); 27 root = null; 28 } 29 inline Node *newNode(int v) { 30 Node *p = tail++; 31 p->set(v, 1, null); 32 return p; 33 } 34 inline void rotate(Node* &x, int d) { 35 Node *k = x->ch[!d]; 36 x->ch[!d] = k->ch[d]; 37 k->ch[d] = x; 38 k->s = x->s; 39 x->push_up(); 40 x = k; 41 } 42 inline void Maintain(Node* &x, int d) { 43 if (x->ch[d] == null) return; 44 if (x->ch[d]->ch[d]->s > x->ch[!d]->s) { 45 rotate(x, !d); 46 } else if (x->ch[d]->ch[!d]->s > x->ch[!d]->s) { 47 rotate(x->ch[d], d), rotate(x, !d); 48 } else { 49 return; 50 } 51 Maintain(x, 0), Maintain(x, 1); 52 } 53 inline void insert(Node* &x, int v) { 54 if (x == null) { 55 x = newNode(v); 56 return; 57 } else { 58 x->s++; 59 int d = x->cmp(v); 60 insert(x->ch[d], v); 61 x->push_up(); 62 Maintain(x, d); 63 } 64 } 65 inline void insert(int v) { 66 insert(root, v); 67 } 68 inline int count(int v) { 69 Node *x = root; 70 int res = 0, t = 0; 71 for (; x->s;) { 72 t = x->ch[0]->s; 73 if (v < x->v) x = x->ch[0]; 74 else res += t + 1, x = x->ch[1]; 75 } 76 return res; 77 } 78 inline int kth(int k) { 79 int t = 0; 80 Node *x = root; 81 if (x->s < k) return -1; 82 for (; x->s;) { 83 t = x->ch[0]->s; 84 if (k == t + 1) break; 85 else if (k <= t) x = x->ch[0]; 86 else k -= t + 1, x = x->ch[1]; 87 } 88 return x->v; 89 } 90 inline int operator[](int k) { 91 return kth(k); 92 } 93 }sbt; 94 int id[5000010]; 95 int main() { 96 #ifdef LOCAL 97 freopen("in.txt", "r", stdin); 98 freopen("out.txt", "w+", stdout); 99 #endif 100 int n, t, x, a, b, k; 101 while (~scanf("%d", &n) && n) { 102 sbt.init(); 103 scanf("%d%d", &t, &x); 104 sbt.insert(x), id[x] = t; 105 printf("%d 1 ", t); 106 for (int i = 2; i <= n; i++) { 107 scanf("%d%d", &t, &x); 108 id[x] = t, k = sbt.count(x); 109 if (!k) a = sbt[1]; 110 else if (k == i - 1) a = sbt[i - 1]; 111 else { 112 a = sbt[k]; 113 b = sbt[k + 1]; 114 if (x - a > b - x) a = b; 115 } 116 printf("%d %d ", t, id[a]); 117 sbt.insert(x); 118 } 119 } 120 return 0; 121 }