题目链接:http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemId=4736
解题思路：在treap里面加上一个num域，用来表示这个节点重复数的个数就行！WA了很多次，发现自己在处理负数的时候有点问题了。然后拿cxlove 的SBT代码比对了一下，时间上差不多，但是空间差距太大了，是他的六倍左右，然后想到应该优化内存，删除节点，最后变成他的 1/3 左右。
解题代码：
1 // File Name: 4736.cpp 2 // Author: darkdream 3 // Created Time: 2014年07月23日 星期三 11时48分03秒 4 5 #include<vector> 6 #include<list> 7 #include<map> 8 #include<set> 9 #include<deque> 10 #include<stack> 11 #include<bitset> 12 #include<algorithm> 13 #include<functional> 14 #include<numeric> 15 #include<utility> 16 #include<sstream> 17 #include<iostream> 18 #include<iomanip> 19 #include<cstdio> 20 #include<cmath> 21 #include<cstdlib> 22 #include<cstring> 23 #include<ctime> 24 #define LL long long 25 using namespace std; 26 int ok = 1; 27 const int inf = ~0U>>1; 28 class treap{ 29 struct node{ 30 int value,key,size,num; 31 node(int v , node *n):value(v) 32 {c[0] = c[1] = n; size = 1;num = 1; key = rand()-1;} 33 void rz(){size = c[0]->size + c[1]->size+ num;} 34 node *c[2]; 35 }*root,*null; 36 void rot(node *&t ,bool d) 37 { 38 node *c = t->c[d]; 39 t->c[d] = c->c[!d]; 40 c->c[!d] = t; 41 t->rz(); 42 c->rz(); 43 t = c; 44 } 45 void insert(node *&t ,int x) 46 { 47 if(t == null) 48 { 49 t= new node(x,null); 50 return ; 51 } 52 if(x == t->value){ 53 t->num++; 54 t->rz(); 55 return ; 56 } 57 bool d = x > t->value; 58 insert(t->c[d],x); 59 if(t->c[d]->key < t->key) 60 rot(t,d); 61 else t->rz(); 62 } 63 void Delete(node *&t,int x) 64 { 65 if(t == null) 66 { 67 ok = 0; 68 return ; 69 } 70 // printf("%d %d %d ",x,t->value,t->num); 71 if(t->value == x && t-> num != 1) 72 { 73 t->num -- ; 74 t->rz(); 75 return ; 76 } 77 if(t->value == x) 78 { 79 bool d= t->c[1]->key < t->c[0]->key; 80 if(t->c[d] == null) 81 { 82 delete t; 83 t = null; 84 return ; 85 } 86 rot(t,d); 87 Delete(t->c[!d],x); 88 }else { 89 bool d = x > t->value; 90 Delete(t->c[d],x); 91 } 92 t->rz(); //相当于pushup 93 } 94 void F(node *t) 95 { 96 if(t == null) 97 return; 98 if(t->c[1] != null) 99 F(t->c[1]); 100 if(t->c[0] != null) 101 F(t->c[0]); 102 delete t; 103 t = null; 104 } 105 int select(node *t ,int k) 106 { 107 int r = t->c[0]->size; 108 int l = t->c[0]->size + t->num; 109 if(k > r && k <= l) 110 { 111 return t->value; 112 } 113 if(k <= r) return select(t->c[0],k); 114 return select(t->c[1],k-l); 115 } 116 public: 117 treap() 118 { 119 null = new node(0,0); 120 null->size = 0 ; 121 null->num = 0 ; 122 null->key = inf; 123 root = null; 124 } 125 void ins(int x) 126 { 127 insert(root ,x); 128 } 129 void del(int x) 130 { 131 Delete(root,x); 132 } 133 void count() 134 { 135 //printf("%d ",k); 136 if(root == null ){ 137 printf("Empty! "); 138 return ; 139 } 140 int k = root->size; 141 if(k % 2 == 1) 142 { 143 printf("%d ",select(root,k/2+1)); 144 }else{ 145 LL temp = 1ll*select(root,k/2) + select(root,k/2+1); 146 if(temp % 2 == 0 ) 147 printf("%lld ",temp/2); 148 else printf("%.1f ",temp*1.0/2); 149 } 150 } 151 void free() 152 { 153 F(root); 154 } 155 156 }; 157 int main(){ 158 //freopen("in.txt","r",stdin); 159 //freopen("output.txt","w",stdout); 160 int ca; 161 scanf("%d",&ca); 162 while(ca --) 163 { 164 int n ; 165 scanf("%d",&n); 166 treap T; 167 for(int i =1 ;i <= n;i ++) 168 { 169 char str[10]; 170 int x; 171 scanf("%s %d",str,&x); 172 if(str[0] == 'r') 173 { 174 ok =1 ; 175 T.del(x); 176 if(ok == 0 ) 177 { 178 printf("Wrong! "); 179 }else{ 180 T.count(); 181 } 182 }else{ 183 T.ins(x); 184 T.count(); 185 } 186 } 187 T.free(); 188 } 189 return 0; 190 }
优化后
| 3706384 | 2014-07-23 20:49:26 | Accepted | 3612 | C++ | 620 | 668 |
优化前
| 3706357 | 2014-07-23 20:33:54 | Accepted | 3612 | C++ | 630 | 12284 | darkdream |