DQUERY  Dquery
English  Vietnamese 
Given a sequence of n numbers a_{1}, a_{2}, ..., a_{n} and a number of dqueries. A dquery is a pair (i, j) (1 ≤ i ≤ j ≤ n). For each dquery (i, j), you have to return the number of distinct elements in the subsequence a_{i}, a_{i+1}, ..., a_{j}.
Input
 Line 1: n (1 ≤ n ≤ 30000).
 Line 2: n numbers a_{1}, a_{2}, ..., a_{n} (1 ≤ a_{i} ≤ 10^{6}).
 Line 3: q (1 ≤ q ≤ 200000), the number of dqueries.
 In the next q lines, each line contains 2 numbers i, j representing a dquery (1 ≤ i ≤ j ≤ n).
Output
 For each dquery (i, j), print the number of distinct elements in the subsequence a_{i}, a_{i+1}, ..., a_{j} 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
alexandro5432:
20181026 20:43:37
offline BIT+very fast io+inline functions+many optimisations=AC


skirim06:
20180929 00:27:56
MO's + fast io + cpp = AC


dipankar12:
20180923 12:13:32
java+mo getting TLE. Anyone solved using JAVA and mo? Last edit: 20180923 12:13:50 

redcenturion:
20180918 08:17:59
Can we solve this by segment tree ? 

lax_99:
20180831 08:26:07
If you're using MO's algorithm, make sure you use array instead of vector and array of frequencies instead of Hash Table. 

bharat133:
20180810 10:47:31
Last edit: 20180810 10:48:11 

sdeven_0245:
20180804 20:17:39
Mo works fine but not the fenwick gives TLE for me.. Last edit: 20180815 18:32:18 

wsrstf:
20180714 16:48:01
I guess this can be solved using slide window method? Sort all query segments and everything is much easier then. 

karan_yadav:
20180710 09:19:03
Was searching for literature on MO (also called Query square root decomposition), found some. I'll list the best of em here:


lamia2658:
20180707 08:52:33
easy MO 
Added by:  Duc 
Date:  20081026 
Time limit:  0.227s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All except: ERL JSRHINO NODEJS PERL6 VB.NET 
Resource:  © VNOI 