Problem:
Score : 600 points

Problem Statement

We have N colored balls arranged in a row from left to right; the color of the i-th ball from the left is c_i.

You are given Q queries. The i-th query is as follows: how many different colors do the l_i-th through r_i-th balls from the left have?

Constraints

1\leq N,Q \leq 5 \times 10^5

1\leq c_i \leq N

1\leq l_i \leq r_i \leq N

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N Q
c_1 c_2 \cdots c_N
l_1 r_1
l_2 r_2
:
l_Q r_Q

Output

Print Q lines. The i-th line should contain the response to the i-th query.

Sample Input 1

4 3
1 2 1 3
1 3
2 4
3 3

Sample Output 1

2
3
1

The 1-st, 2-nd, and 3-rd balls from the left have the colors 1, 2, and 1 - two different colors.

The 2-st, 3-rd, and 4-th balls from the left have the colors 2, 1, and 3 - three different colors.

The 3-rd ball from the left has the color 1 - just one color.

Sample Input 2

10 10
2 5 6 5 2 1 7 9 7 2
5 5
2 4
6 7
2 2
7 8
7 9
1 8
6 9
8 10
6 8

Sample Output 2

1
2
2
1
2
2
6
3
3
3

Solution in Julia (1.4.0) (judge verdict: Wrong Answer)

using DataStructures
const double = Float64
const int = Int64

parseint(x) = parse(int, x)
readint() = map(parseint, split(readline()))

function cutN(A,L)
  N = length(A)
  c = 0
  for i in 1:N
    c += A[i]÷L
    if A[i]%L == 0
      c -= 1
    end
  end
  return c
end

function main()
  N,K = readint()
  A = readint()

  LB = 0
  for i in 1:N
    if LB < A[i]
      LB = A[i]
    end
  end
  LA = 1
  #LB = 10^9
  KA = cutN(A,LA)
  KB = cutN(A,LB)

  if KB == K
    println(LB)
    return
  elseif KA <= K
    println(LA)
    return
  end

  while true
  LC = (LA + LB)÷2
  KC = cutN(A,LC)
  if cutN(A,LC) <= K < cutN(A,LC-1)
    println(LC)
    return
  end

  if cutN(A,LC-1) <= K
    LB = LC
  else
    LA = LC
  end

  #println(KA," ", KB," ", KC)
end  



end

main()