思路:裸的划分树 #include<iostream> #include<algorithm> #include<cstring> #include<cstdio> #include<algorithm> #include<cmath> #define Maxn 100010 #define inf 0x7fffffff #define lson(x) (x<<1) #define rson(x) ((x<<1…

Kth number Time Limit: 15000/5000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 6951    Accepted Submission(s): 2214 Problem Description Give you a sequence and ask you the kth big number of a inteval.   Input The…

题目链接:  http://acm.hdu.edu.cn/showproblem.php?pid=4417 题目大意:给定一个区间,以及一个k值,求该区间内小于等于k值的数的个数.注意区间是从0开始的. 解题思路: 首先这题线段树可以解.方法是维护一个区间最大值max,一个区间点个数s,如果k>max,则ans=s+Q(rson),否则ans=Q(lson). 然后也可以用求区间第K大的划分树来解决,在对原来求第K大的基础上改改就行,方法如下: Build方法同第K大. 对于Query: ①左区…

思路:裸的划分树 #include<iostream> #include<algorithm> #include<cstdio> #include<cmath> #include<cstring> #define Maxn 100010 #define lson(x) x<<1 #define rson(x) x<<1|1 #define mid ((tree[po].l+tree[po].r)>>1) usi…

思路:二分枚举区间第k大.用划分树查找是否符合要求的高度. #include<iostream> #include<algorithm> #include<cstdio> #include<cmath> #include<cstring> #define Maxn 100010 #define lson(x) x<<1 #define rson(x) x<<1|1 #define mid ((tree[po].l+tree…

Problem Description Mario is world-famous plumber. His “burly” figure and amazing jumping ability reminded in our memory. Now the poor princess is in trouble again and Mario needs to save his lover. We regard the road to the boss’s castle as a line (…

题意:有n个数.m个询问(l,r,k),问在区间[l,r] 有多少个数小于等于k. 划分树--查找区间第k大的数.... 利用划分树的性质.二分查找在区间[l,r]小于等于k的个数. 假设在区间第 i 大的数tmp>k,则往下找,假设tmp<k,往上找.   #include<cstdio> #include<stdlib.h> #include<string.h> #include<string> #include<map> #in…

两道题都是区间第K大询问,数据规模基本相同. 解决这种问题, 可以采用平方划分(块状表)复杂度也可以接受,但是实际表现比主席树差得多. 这里大致讲一下我对主席树的理解. 首先,如果对于某个区间[L,R],对这个区间排序后,我们构造出了线段树, 每个值在这个子区间出现了几次都可以从线段树中查询,我们就可以在对数时间解决询问. 现在的问题就是怎样在时空复杂度O(nlogn)的时间内构造出这么多的线段树! 1.首先对原序列a排序并删去重复得到新序列b 2.对a的每个前缀构造线段树,即a的前i个数出现在…

Kth number                                                 Time Limit: 15000/5000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)                                                                        Total Submission(s): 10682    Accep…

Minimum Sum Time Limit: 16000/8000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 3611    Accepted Submission(s): 829 Problem Description You are given N positive integers, denoted as x0, x1 ... xN-1. Then give you…