主要综合借鉴了yyb和马前卒两位大佬的。
1 //普通平衡树 2 #include <cstdio> 3 #include <cctype> 4 #include <cstring> 5 #include <algorithm> 6 #define R(x) scanf("%d", &x) 7 #define ri readint() 8 #define gc getchar() 9 #define wi(x) printf("%d\n", x) 10 #define ls(x) T[x].ch[0] 11 #define rs(x) T[x].ch[1] 12 using namespace std; 13 14 int readint() { 15 int x = 0, s = 1, c = gc; 16 while (c <= 32) c = gc; 17 if (c == '-') s = -1, c = gc; 18 for (; isdigit(c); c = gc) 19 x = x * 10 + c - 48; 20 return x * s; 21 } 22 23 struct node { 24 int fa; 25 int ch[2]; 26 int val, cnt; 27 int size; 28 }; 29 node T[100005]; 30 int tot, root; 31 32 int lr(int x) { 33 return x == rs(T[x].fa); 34 } 35 36 void Connect(int son, int fa, int way) { 37 T[fa].ch[way] = son; 38 T[son].fa = fa; 39 } 40 41 void push_up(int pos) { 42 T[pos].size = T[ls(pos)].size + T[rs(pos)].size + T[pos].cnt; 43 } 44 45 void Rotate(int x) { 46 int f = T[x].fa, gf = T[f].fa; 47 int x_f = lr(x), f_gf = lr(f); 48 Connect(T[x].ch[x_f^1], f, x_f); 49 Connect(f, x, x_f^1); 50 Connect(x, gf, f_gf); 51 push_up(f); 52 push_up(x); 53 } 54 55 void splay(int pos, int goal) { 56 for (; T[pos].fa != goal; Rotate(pos)) { 57 int f = T[pos].fa, gf = T[f].fa; 58 if (gf != goal) { 59 lr(f) ^ lr(pos) ? Rotate(pos) : Rotate(f); 60 } 61 } 62 if (goal == 0) root = pos; 63 } 64 65 void Insert(int x) { 66 int pos = root, fa = 0; 67 while (pos && T[pos].val != x) { 68 fa = pos; 69 pos = T[pos].ch[x > T[pos].val]; 70 } 71 if (pos) { 72 T[pos].cnt++; 73 } else { 74 pos = ++tot; 75 if (fa) T[fa].ch[x > T[fa].val] = pos; 76 T[pos].ch[0] = T[pos].ch[1] = 0; 77 T[pos].fa = fa; 78 T[pos].val = x; 79 T[pos].cnt = T[pos].size = 1; 80 } 81 splay(pos, 0); 82 } 83 84 int find(int x) {//数字val为x的位置 85 int pos = root; 86 if (!pos) return 0; 87 while (T[pos].ch[x > T[pos].val] && x != T[pos].val) 88 pos = T[pos].ch[x > T[pos].val]; 89 splay(pos, 0); 90 return pos; 91 } 92 93 int Next(int flag, int x) {//0为前驱，1为后继 94 find(x); 95 int pos = root; 96 if (T[pos].val > x && flag) return pos; 97 if (T[pos].val < x && !flag) return pos; 98 pos = T[pos].ch[flag]; 99 while (T[pos].ch[flag^1]) { 100 pos = T[pos].ch[flag^1]; 101 } 102 return pos; 103 } 104 105 void Delet(int x) {//删除数字x 106 int pos = find(x); 107 if (!pos) return; 108 if (T[pos].cnt > 1) { 109 T[pos].cnt--; 110 T[pos].size--; 111 return; 112 } else { 113 if (!ls(pos) && !rs(pos)) { 114 root = 0; 115 return; 116 } else if (ls(pos) && rs(pos)) { 117 int u = ls(pos); 118 while (rs(u)) u = rs(u); 119 splay(u, 0); 120 Connect(rs(pos), u, 1); 121 push_up(u); 122 } else { 123 if (ls(pos)) root = ls(pos); 124 else root = rs(pos); 125 T[root].fa = 0; 126 } 127 } 128 } 129 130 int Rank(int x) {//数字x的排名 131 find(x); 132 return T[ls(root)].size + 1; 133 } 134 135 int Kth(int x) {//第x大的数 136 int pos = root; 137 if (T[pos].size < x) return -1; 138 while (true) { 139 int lson = ls(pos); 140 if (x > T[lson].size + T[pos].cnt) { 141 x -= T[lson].size + T[pos].cnt; 142 pos = rs(pos); 143 } else { 144 if (x > T[lson].size) return T[pos].val;//这个题返回的是值 145 pos = lson; 146 } 147 } 148 } 149 150 int main() { 151 int n; 152 for (n = ri; n; n--) { 153 int op = ri, x = ri; 154 if (op == 1) Insert(x); 155 else if (op == 2) Delet(x); 156 else if (op == 3) wi(Rank(x)); 157 else if (op == 4) wi(Kth(x)); 158 else wi(T[Next(op - 5, x)].val); 159 } 160 return 0; 161 }
1 //文艺平衡树 2 #include <cstdio> 3 #include <cctype> 4 #include <iostream> 5 #include <algorithm> 6 #define ri readint() 7 #define gc getchar() 8 #define init(a, b) memset(a, b, sizeof(a)) 9 #define rep(i, a, b) for (int i = a; i <= b; i++) 10 #define irep(i, a, b) for (int i = a; i >= b; i--) 11 #define ls(x) T[x].ch[0] 12 #define rs(x) T[x].ch[1] 13 using namespace std; 14 15 typedef double db; 16 typedef long long ll; 17 typedef unsigned long long ull; 18 typedef pair<int, int> P; 19 const int inf = 0x3f3f3f3f; 20 const ll INF = 1e18; 21 22 inline int readint() { 23 int x = 0, s = 1, c = gc; 24 while (!isdigit(c)) c = gc; 25 if (c == '-') s = -1, c = gc; 26 for (; isdigit(c); c = gc) 27 x = x * 10 + c - 48; 28 return x * s; 29 } 30 31 const int maxn = 1e5 + 5; 32 int n, m, root, tot; 33 struct node { 34 int fa, ch[2]; 35 int val, size, tag; 36 }; 37 node T[maxn]; 38 39 int lr(int x) { 40 return x == T[T[x].fa].ch[1]; 41 } 42 43 void connect(int son, int fa, int way) { 44 T[son].fa = fa; 45 T[fa].ch[way] = son; 46 } 47 48 void push_down(int pos) { 49 if (T[pos].tag) { 50 T[ls(pos)].tag ^= 1; 51 T[rs(pos)].tag ^= 1; 52 T[pos].tag = 0; 53 swap(ls(pos), rs(pos)); 54 } 55 } 56 57 void push_up(int pos) { 58 T[pos].size = T[ls(pos)].size + T[rs(pos)].size + 1; 59 } 60 61 void rotate(int pos) { 62 int f = T[pos].fa, gf = T[f].fa; 63 int x_f = lr(pos), f_gf = lr(f); 64 connect(T[pos].ch[x_f^1], f, x_f); 65 connect(f, pos, x_f^1); 66 connect(pos, gf, f_gf); 67 push_up(f); 68 push_up(pos); 69 } 70 71 void splay(int pos, int goal) { 72 for (; T[pos].fa != goal; rotate(pos)) { 73 int f = T[pos].fa, gf = T[f].fa; 74 if (gf != goal) 75 lr(pos) ^ lr(f) ? rotate(pos) : rotate(f); 76 } 77 if (!goal) root = pos; 78 } 79 80 void insert(int x) { 81 int pos = root, fa = 0; 82 while (pos && T[pos].val != x) { 83 fa = pos; 84 pos = T[pos].ch[x > T[pos].val]; 85 } 86 pos = ++tot; 87 if (fa) T[fa].ch[x > T[fa].val] = pos; 88 T[pos].fa = fa; 89 T[pos].ch[0] = T[pos].ch[1] = 0; 90 T[pos].val = x; 91 T[pos].size = 1; 92 T[pos].tag = 0; 93 splay(pos, 0); 94 } 95 96 int Kth(int x) { 97 int pos = root; 98 while (true) { 99 push_down(pos); 100 int lson = ls(pos); 101 if (x > T[lson].size + 1) { 102 x -= T[lson].size + 1; 103 pos = rs(pos); 104 } else { 105 if (x > T[lson].size) return pos; 106 pos = lson; 107 } 108 } 109 } 110 111 void work(int l, int r) { 112 l = Kth(l), r = Kth(r + 2); 113 splay(l, 0), splay(r, l); 114 int pos = rs(root); 115 pos = ls(pos); 116 T[pos].tag ^= 1; 117 } 118 119 void dfs(int cur) { 120 push_down(cur); 121 if (T[cur].ch[0]) dfs(T[cur].ch[0]); 122 if (T[cur].val != -inf && T[cur].val != inf) 123 printf("%d ", T[cur].val); 124 if (T[cur].ch[1]) dfs(T[cur].ch[1]); 125 } 126 127 int main() { 128 n = ri, m = ri; 129 insert(inf), insert(-inf); 130 rep(i, 1, n) insert(i); 131 while (m--) { 132 int l = ri, r = ri; 133 work(l, r); 134 } 135 dfs(root); 136 return 0; 137 }
