DQUERY - D-query


Given a sequence of n numbers a1, a2, ..., an and a number of d-queries. A d-query is a pair (i, j) (1 ≤ i ≤ j ≤ n). For each d-query (i, j), you have to return the number of distinct elements in the subsequence ai, ai+1, ..., aj.

Input

  • Line 1: n (1 ≤ n ≤ 30000).
  • Line 2: n numbers a1, a2, ..., an (1 ≤ ai ≤ 106).
  • Line 3: q (1 ≤ q ≤ 200000), the number of d-queries.
  • In the next q lines, each line contains 2 numbers i, j representing a d-query (1 ≤ i ≤ j ≤ n).

Output

  • For each d-query (i, j), print the number of distinct elements in the subsequence ai, ai+1, ..., aj in a single line.

     

Example

Input
5
1 1 2 1 3
3
1 5
2 4
3 5

Output
3
2
3 


hide comments
sicho_mohit: 2021-07-28 08:23:18

If you want to solve this using segment tree.
Here are some of the hints.
HINT 1:Iterating the array for i=0;i<n;
HINT 2:Think treating each i as an R(right range) of a query(l,r).
HINT 3:Try considering all the ranges for that particular i(acting as r) which we have).
HINT 4:Now to maintain distinct elements in that range.
You can also read this blog https://codeforces.com/blog/entry/8962?#comment-146571

Last edit: 2021-07-28 08:28:57
hackerbhaiya: 2021-06-23 20:57:54

AC with square root decomposition on arrays only. No need to use MO here. This problem can be reduced to KQUERY problem on spoj.

prakrat: 2021-06-15 00:05:33

Solved using MO's

omar622: 2021-05-22 00:19:50

AC with MO algorithm


Added by:Jimmy
Date:2008-10-26
Time limit:1s-1.5s
Source limit:50000B
Memory limit:1536MB
Cluster: Cube (Intel G860)
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