就是裸的平衡树的说= =
怎么就是做不出呢。。。
直接写Treap好了，反正Splay至今不会233
1 /************************************************************** 2 Problem: 3224 3 User: rausen 4 Language: C++ 5 Result: Accepted 6 Time:212 ms 7 Memory:4032 kb 8 ****************************************************************/ 9 10 #include <cstdio> 11 #include <cstdlib> 12 #include <ctime> 13 14 #define lson tr[r].l 15 #define rson tr[r].r 16 using namespace std; 17 const int N = 100001; 18 const int Maxlen = 900005; 19 20 struct treap_node { 21 int l, r, v, sz, key, cnt; 22 }tr[N]; 23 24 int n, cnt, root, ans, x; 25 char buf[Maxlen]; 26 int Left, Len; 27 28 inline int read() { 29 int x = 0, sgn = 1; 30 while (buf[Left] < '0' || '9' < buf[Left]) 31 if (buf[Left++] == '-') sgn = -1; 32 while ('0' <= buf[Left] && buf[Left] <= '9') 33 x = x * 10 + buf[Left++] - '0'; 34 return sgn * x; 35 } 36 37 int len = 0, pr[15]; 38 inline void print(int x) { 39 if (x < 0) putchar('-'), x = -x; 40 while (x) 41 pr[++len] = x % 10, x /= 10; 42 if (!len) putchar('0'); 43 while (len) 44 putchar(pr[len--] + '0'); 45 puts(""); 46 } 47 48 49 inline void update(int r) { 50 tr[r].sz = tr[lson].sz + tr[rson].sz + tr[r].cnt; 51 } 52 53 inline void rturn(int &r) { 54 int t = lson; 55 lson = tr[t].r; 56 tr[t].r = r, tr[t].sz = tr[r].sz; 57 update(r); 58 r = t; 59 } 60 61 inline void lturn(int &r) { 62 int t = rson; 63 rson = tr[t].l; 64 tr[t].l = r, tr[t].sz = tr[r].sz; 65 update(r); 66 r = t; 67 } 68 69 void ins(int &r) { 70 if (r == 0) { 71 r = ++cnt; 72 tr[r].sz = tr[r].cnt = 1; 73 tr[r].v = x; 74 tr[r].key = rand(); 75 return; 76 } 77 ++tr[r].sz; 78 if (tr[r].v == x) 79 ++tr[r].cnt; 80 else if (x > tr[r].v) { 81 ins(rson); 82 if (tr[rson].key < tr[r].key) 83 lturn(r); 84 } else { 85 ins(lson); 86 if (tr[lson].key < tr[r].key) 87 rturn(r); 88 } 89 } 90 91 void del(int &r) { 92 if (r == 0) return; 93 if (tr[r].v == x) { 94 if (tr[r].cnt > 1) { 95 --tr[r].cnt, --tr[r].sz; 96 return; 97 } 98 if (!lson || !rson) 99 r = lson + rson; 100 else if (tr[lson].key < tr[rson].key) 101 rturn(r), del(r); 102 else lturn(r), del(r); 103 } 104 else if (x > tr[r].v) --tr[r].sz, del(rson); 105 else --tr[r].sz, del(lson); 106 } 107 108 int query_rank(int r) { 109 if (r == 0) return 0; 110 if (tr[r].v == x) 111 return tr[lson].sz + 1; 112 else if (x > tr[r].v) 113 return tr[lson].sz + tr[r].cnt + query_rank(rson); 114 return query_rank(lson); 115 } 116 117 int query_kth (int r, int x) { 118 if (r == 0) return 0; 119 if (x <= tr[lson].sz) return query_kth(lson, x); 120 else if (x > tr[lson].sz + tr[r].cnt) 121 return query_kth(rson, x - tr[lson].sz - tr[r].cnt); 122 else return tr[r].v; 123 } 124 125 void query_pre(int r) { 126 if (r == 0) return; 127 if (tr[r].v < x) { 128 ans = r; 129 query_pre(rson); 130 } else query_pre(lson); 131 } 132 133 void query_next(int r) { 134 if (r == 0) return; 135 if (tr[r].v > x) { 136 ans = r; 137 query_next(lson); 138 } else query_next(rson); 139 } 140 141 int main() { 142 int i, oper; 143 Len = fread(buf, 1, Maxlen, stdin); 144 buf[Len] = ' '; 145 n = read(); 146 for (i = 1; i <= n; ++i) { 147 oper = read(), x = read(); 148 if (oper == 1) 149 ins(root); else 150 if (oper == 2) 151 del(root); else 152 if (oper == 3) 153 print(query_rank(root)); else 154 if (oper == 4) 155 print(query_kth(root, x)); else 156 if (oper == 5) { 157 ans = 0, query_pre(root); 158 print(tr[ans].v); 159 } else 160 if (oper == 6) { 161 ans = 0, query_next(root); 162 print(tr[ans].v); 163 } 164 } 165 return 0; 166 }