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 PyPy3 (7.3.0) (judge verdict: Wrong Answer)

import copy
N,Q=map(int,input().split())
Cs=list(map(int,input().split()))

AllCs=list(set(sorted(Cs)))
Each=[0]*len(AllCs)
Cum=[]
Cum.append(Each)

index=0
for c in Cs:
  #print(c)
  #print(Cum)
  if index>0:
    newappend=copy.copy(Cum[-1])
    Cum.append(newappend)

  for i in range(len(AllCs)):
    if AllCs[i]==c:
      #rint(index)
      Cum[index][i]+=1
      break
  index+=1      

#print(Cum)

for i in range(Q):
  l,r = map(int,input().split())
  numall=0
  for k in range(len(AllCs)):
    #print(k)
    if l==1:
      ushiro=0
    else:
      ushiro=l-2
    
    if Cum[r-1][k]-Cum[ushiro][k]>0:
      numall+=1
  #print("-----",l,r)
  print(numall)