题目
详情见链接。
代码
1 #include<cstdio> 2 #include<iostream> 3 #define outd(x) printf("%d ",x) 4 #define outld(x) printf("%lld ", x) 5 #define ls(x) arr[x].child[0] 6 #define rs(x) arr[x].child[1] 7 inline int read_int() 8 { 9 char c; 10 int ret = 0, sgn = 1; 11 do { c = getchar(); } while ((c < '0' || c > '9') && c != '-'); 12 if (c == '-') sgn = -1; else ret = c - '0'; 13 while ((c = getchar()) >= '0' && c <= '9') ret = ret * 10 + (c - '0'); 14 return sgn * ret; 15 } 16 using namespace std; 17 18 const int maxn = 100000 + 10; 19 20 struct node 21 { 22 int child[2], size, value, key; 23 }arr[maxn]; 24 int tot; //当前节点个数 25 26 27 28 inline void push_up(int index) 29 { 30 arr[index].size = arr[ls(index)].size + arr[rs(index)].size + 1; 31 } 32 33 void split(int root, int& x, int& y, int value) //x中的小于或等于value，y中的大于value 34 { 35 if (!root) { x = y = 0; return; } 36 if (arr[root].value <= value) { x = root; split(rs(root), rs(x), y, value); } 37 else { y = root; split(ls(root), x, ls(y), value); } 38 push_up(root); 39 } 40 41 void merge(int&root, int x, int y) 42 { 43 if (!x || !y) { root = x + y; return; } //其中一个为0，root等于另一个 44 if (arr[x].key < arr[y].key) { root = x; merge(rs(root), rs(x), y); } 45 else { root = y; merge(ls(root), x,ls(y)); } 46 push_up(root); 47 } 48 49 inline void insert(int& root, int value) 50 { 51 int x = 0, y = 0, z = ++tot; 52 arr[z].value = value, arr[z].size = 1, arr[z].key = rand(); 53 split(root, x, y, value); 54 merge(x, x, z); 55 merge(root, x, y); 56 } 57 58 inline void erase(int& root, int value) 59 { 60 int x = 0, y = 0, z = 0; 61 split(root, x, y, value); 62 split(x, x, z, value - 1); //z中全是value 63 merge(z, ls(z), rs(z)); 64 merge(x, x, z); 65 merge(root, x, y); 66 } 67 68 inline int Kth_number(int root, int k) 69 { 70 while (arr[ls(root)].size + 1 != k) 71 { 72 if (arr[ls(root)].size >= k) root = ls(root); 73 else { k -= (arr[ls(root)].size + 1); root = rs(root); } 74 } 75 return arr[root].value; 76 } 77 78 inline int Get_rank(int& root, int value) 79 { 80 int x = 0, y = 0; 81 split(root, x, y, value - 1); 82 int res = arr[x].size + 1; 83 merge(root, x, y); 84 return res; 85 } 86 87 inline int Pre(int& root, int value) 88 { 89 int x = 0, y = 0; 90 split(root, x, y, value - 1); 91 int res = Kth_number(x, arr[x].size); 92 merge(root, x, y); //merge回去 93 return res; 94 } 95 96 inline int Suf(int& root, int value) 97 { 98 int x = 0, y = 0; 99 split(root, x, y,value); 100 int res = Kth_number(y, 1); 101 merge(root, x, y); 102 return res; 103 } 104 105 int n, op, root; 106 107 int main() 108 { 109 srand(19260817); 110 n = read_int(); 111 while (n--) 112 { 113 op = read_int(); 114 if (op == 1) insert(root, read_int()); 115 if (op == 2) erase(root, read_int()); 116 if (op == 3) outd(Get_rank(root, read_int())); 117 if (op == 4) outd(Kth_number(root, read_int())); 118 if (op == 5) outd(Pre(root, read_int())); 119 if (op == 6) outd(Suf(root, read_int())); 120 } 121 122 return 0; 123 }