题目链接:Codeforces 85D - Sum of Medians 题目大意:N个操作,add x:向集合中加入x:del x:删除集合中的x:sum:将集合排序后,将集合中全部下标i % 5 = 3的元素累加求和. 解题思路:线段树单点更新,每一个点维护5个值.分别表示从该段区间中i % 5 = t的和.然后两端区间合并时仅仅须要依据左孩子中元素的个数合并.所以有一个c表示区间上元素的个数. 由于有同样的数.所以要离线操做,将全部的数映射成位置,可是对于del则不须要映射,由于集合中肯定…

传送门 D. Sum of Medians time limit per test 3 seconds memory limit per test 256 megabytes input standard input output standard output In one well-known algorithm of finding the k-th order statistics we should divide all elements into groups of five con…

D. Sum of Medians time limit per test 3 seconds memory limit per test 256 megabytes input standard input output standard output In one well-known algorithm of finding the k-th order statistics we should divide all elements into groups of five consecu…

传送门 题目 In one well-known algorithm of finding the k-th order statistics we should divide all elements into groups of five consecutive elements and find the median of each five. A median is called the middle element of a sorted array (it's the third l…

Sum of Medians 题解: 对于这个题目,先想到是建立5棵Splay,然后每次更新把后面一段区间的树切下来,然后再转圈圈把切下来的树和别的树合并. 但是感觉写起来太麻烦就放弃了. 建立5棵线段树. 然后 seg[rt][i]代表的是只考虑当前所管辖的区间中的情况下, 下标对5取余之后为 i 的那些值的和. 最重要的一点是更新. ; i < ; ++i) seg[i][rt] = seg[i][rt<<] + seg[((i-sz[rt<<]%)+)%][rt<…

http://codeforces.com/problemset/problem/85/D 题意: 给你N(0<N<1e5)次操作,每次操作有3种方式, 1.向集合里加一个数a(0<a<1e9)(增加数a之前的集合一定不存在a) 2.向集合里删一个数a(0<a<1e9)(删除数a之前的集合一定存在a) 3.将下标i%5==3的数相加,计算总和并相加. 分析: 先离散,然后线段树,sum[i]用来标识前i项有几个数,ans[rt][i]表示以rt为根的子树中第i大数的和…

D. Sum of Medians time limit per test 3 seconds memory limit per test 256 megabytes input standard input output standard output In one well-known algorithm of finding the k-th order statistics we should divide all elements into groups of five consecu…

D. Sum of Medians Time Limit: 1 Sec  Memory Limit: 256 MB 题目连接 http://codeforces.com/problemset/problem/85/D Description In one well-known algorithm of finding the k-th order statistics we should divide all elements into groups of five consecutive el…

题目链接: Sum of Medians Time Limit:3000MSMemory Limit:262144KB 问题描述 In one well-known algorithm of finding the k-th order statistics we should divide all elements into groups of five consecutive elements and find the median of each five. A median is cal…

D. Sum of Medians time limit per test 3 seconds memory limit per test 256 megabytes input standard input output standard output In one well-known algorithm of finding the k-th order statistics we should divide all elements into groups of five consecu…