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 (Python):
import sys
input = sys.stdin.readline

class BIT:
    def __init__(self, n):
        self.n = n
        self.data = [0]*(n+1)
        self.el = [0]*(n+1)
    def sum(self, i):
        s = 0
        while i > 0:
            s += self.data[i]
            i -= i & -i
        return s
    def add(self, i, x):
        
        self.el[i] += x
        while i <= self.n:
            self.data[i] += x
            i += i & -i
    def get(self, i, j=None):
        if j is None:
            return self.el[i]
        return self.sum(j) - self.sum(i)

n,q=map(int,input().split())
c=list(map(int,input().split()))
ques=[]
from collections import defaultdict
ans=defaultdict(int)
for _ in range(q):
    l,r=map(int,input().split())
    ques.append((l,r))

sortques=sorted(ques, key=lambda x:x[1])

good=BIT(n+1)
goodind=[-1]*n
last=0
for x in range(q):
    l,r=sortques[x]
    if last!=r:
        for i in range(last, r):
            if goodind[c[i]-1]==-1:
                goodind[c[i]-1]=i
                good.add(i+1, 1)
            else:
                j=goodind[c[i]-1]
                good.add(j+1, -1)
                goodind[c[i]-1]=i
                good.add(i+1, 1)
    ans[(l,r)]=good.get(l-1,r)
    last=r

for i in range(q):
    print(ans[ques[i]])

Solution (Python):
import sys

sys.setrecursionlimit(500000)
def input():
    return sys.stdin.readline()[:-1]


class BIT:
            
    def __init__(self, L):
        self.N = len(L)
        self.bit = [0]*self.N
        for i,l in enumerate(L):
            self.add(i,l)
        self.N0 = 1
        while self.N0*2 <= self.N:
            self.N0 *= 2

    def add(self, a, w):
        x = a + 1
        for i in range(1000):
            self.bit[x-1] += w
            x += x & -x
            if x > self.N:
                break

    def sum(self, a):
        x = a+1
        ret = 0
        for i in range(1000):
            ret += self.bit[x-1]
            x -= x & -x
            if x <= 0:
                break        
        return ret

    
    def lower_bound(self, w):
        if w<=0:
            return 0
        x = 0
        k = self.N0
        while k>0:
            if x+k<=self.N:
                if self.bit[x+k-1]<w:
                    w-=self.bit[x+k-1]
                    x+=k
            k//=2
        return x

def main():
    N,Q = list(map(int,input().split()))
    c = list(map(int,input().split()))

    LR = []

    for i in range(Q):
        l,r = list(map(int,input().split()))
        LR.append((l-1,r-1,i))

    LR.sort(key=lambda x:x[1])


    bit = BIT([0]*N)
    ans = [0]*Q
    count = 0
    last_one = [-1]*N
    for l,r,i in LR:
        while count<=r:
            color = c[count]-1
            if last_one[color]==-1:
                last_one[color] = count
                bit.add(last_one[color],1)
            else:
                bit.add(last_one[color],-1)
                last_one[color] = count
                bit.add(last_one[color],1)
            count+=1
        if l==0:
            ans[i] = bit.sum(r)
        else:
            ans[i] = bit.sum(r) - bit.sum(l-1)
    print(*ans,sep="\n")

if __name__ == '__main__':
    main()

Solution (Python):
import sys
input = sys.stdin.readline

def main():
    N, Q = map(int, input().split())
    bit = [0] * (N+1)

    def add(x, a):
        while x <= N:
            bit[x] += a
            x += x & -x

    def sum(x):
        ret = 0
        while x != 0:
            ret += bit[x]
            x -= x & -x
        return ret

    c = list(map(int, input().split()))
    lr = [None] * Q
    for i in range(Q):
        l, r = map(int, input().split())
        lr[i] = (i, l, r)
    lr.sort(key=lambda x: x[2])
    ans = [None] * Q
    last_idx = [-1] * (N+1)
    j = 0
    for i, l, r in lr:
        while j < r:
            if last_idx[c[j]] == -1:
                last_idx[c[j]] = j
            else:
                add(last_idx[c[j]]+1, -1)
                last_idx[c[j]] = j
            add(j+1, 1)
            j += 1
        ans[i] = sum(r) - sum(l-1)
    for a in ans:
        print(a)
            
if __name__ == "__main__":
    main()

Solution (Python):
def main():
    import sys
    input = sys.stdin.readline
    class BIT:
        def __init__(self,n):
            self.tree = [0]*(n+1)
            self.size = n
        
        def add(self,i,x):
            while i <= self.size:
                self.tree[i] += x
                i += i&-i
        
        def sum(self,i):
            s = 0
            while i > 0:
                s += self.tree[i]
                i -= i&-i
            return s

    N,Q = map(int,input().split())
    bit = BIT(N)
    C = list(map(int,input().split()))
    query = []
    for i in range(Q):
        l,r = map(int,input().split())
        query.append([l,r,i])
    query.sort(key=lambda x: x[1])
    ans = [0]*Q
    
    colorMemo = [0]*(N+1)
    cur = 1
    for q in query:
        l,r,j = q
        
        for i in range(cur,r+1):
            c = C[i-1]
            if colorMemo[c]:
                bit.add(colorMemo[c],-1)
            bit.add(i,1)
            colorMemo[c] = i
        cur = r + 1
        ans[j]=bit.sum(r)-bit.sum(l-1)

    for a in ans:
        print(a)
main()

Solution (Python):
def main():
    import sys
    input = sys.stdin.readline
    class BIT:
        def __init__(self,n):
            self.tree = [0]*(n+1)
            self.size = n
        
        def add(self,i,x):
            while i <= self.size:
                self.tree[i] += x
                i += i&-i
        
        def sum(self,i):
            s = 0
            while i > 0:
                s += self.tree[i]
                i -= i&-i
            return s

    N,Q = map(int,input().split())
    bit = BIT(N)
    C = list(map(int,input().split()))
    query = []
    for i in range(Q):
        l,r = map(int,input().split())
        query.append([l,r,i])
    query.sort(key=lambda x: x[1])
    ans = [0]*Q
    
    colorMemo = [0]*(N+1)
    cur = 1
    for q in query:
        l,r,j = q
        
        for i in range(cur,r+1):
            c = C[i-1]
            if colorMemo[c]:
                bit.add(colorMemo[c],-1)
            bit.add(i,1)
            colorMemo[c] = i
        cur = r + 1
        ans[j]=bit.sum(r)-bit.sum(l-1)

    print(*ans, sep="\n")
main()

Solution (Python):

class BIT:
    
    def __init__(self, n):
        self.size = n + 1
        self.bit = [0] * self.size

    def add(self, i, x):
        
        while i < self.size:
            self.bit[i] += x
            i += i & -i

    def sumup(self, i):
        
        res = 0
        while i > 0:
            res += self.bit[i]
            i -= i & -i
        return res

    def query(self, i, j):
        
        return self.sumup(j) - self.sumup(i - 1)


N, Q = map(int, input().split())
C = list(map(int, input().split()))

X = []
for i in range(Q):
    l, r = map(int, input().split())
    X.append((i, l, r))
X.sort(key=lambda x: x[2])

ans = [0] * Q
bit = BIT(N + 1)
last = [0] * (N + 1)
k = 0
for i, l, r in X:
    for j in range(k + 1, r + 1):
        if last[C[j - 1]] > 0:
            bit.add(last[C[j - 1]], -1)

        bit.add(j, 1)
        last[C[j - 1]] = j

    k = r
    ans[i] = bit.query(l, r)

print(*ans, sep="\n")

Solution (Python):
class BinaryIndexedTree():
    def __init__(self, max_n):
        self.size = max_n + 1
        self.tree = [0] * self.size
        self.depth = self.size.bit_length()
 
    def initialize(self, seq):
        for i, x in enumerate(seq[1:], 1):
            self.tree[i] += x
            j = i + (i & (-i))
            if j < self.size:
                self.tree[j] += self.tree[i]
 
    def __repr__(self):
        return self.tree.__repr__()
 
    def get_sum(self, i):
        s = 0
        while i:
            s += self.tree[i]
            i -= i & -i
        return s
 
    def add(self, i, x):
        while i < self.size:
            self.tree[i] += x
            i += i & -i
 
    def find_kth_element(self, k):
        x, sx = 0, 0
        dx = (1 << self.depth)
        for i in range(self.depth - 1, -1, -1):
            dx = (1 << i)
            if x + dx >= self.size:
                continue
            y = x + dx
            sy = sx + self.tree[y]
            if sy < k:
                x, sx = y, sy
        return x + 1
"""
n = 2*10**5
bit = BinaryIndexedTree(n) 
bit.add(1,1) 
"""


n,q = map(int,input().split())
c = [0]+list(map(int,input().split()))
query = [list(map(int,input().split()))+[i] for i in range(q)]
query.sort(key=lambda x:x[1])

memo = [0]*(n+1)
ans = [0]*q

bit = BinaryIndexedTree(n)
now = 0
for i in range(q):
    l,r,ind = query[i]
    for j in range(now+1,r+1):
        color = c[j]
        if memo[color] == 0:
            memo[color] = j
            bit.add(j,1)
        else:
            bit.add(memo[color],-1)
            bit.add(j,1)
            memo[color] = j
    now = r
    ans[ind] = bit.get_sum(r)-bit.get_sum(l-1)

for a in ans:
    print(a)

Solution (Python):
import sys
import numpy as np

read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

Bsize = 700

def Mo_argsort(LR):
    L = LR[:, 0]
    R = LR[:, 1]
    key1 = L // Bsize
    key2 = np.where(key1 & 1, -R, R)
    key = (key1 << 32) + key2
    return np.argsort(key)

def main(A, LR):
    N = len(A)
    Q = len(LR)
    ind = Mo_argsort(LR)
    count = np.zeros(N + 1, np.int32)
    ans = 0

    def add(x):
        nonlocal ans
        if not count[x]:
            ans += 1
        count[x] += 1

    def rem(x):
        nonlocal ans
        count[x] -= 1
        if not count[x]:
            ans -= 1

    answers = np.empty(Q, np.int32)
    nl, nr = 0, 0
    for i in ind:
        l, r = LR[i]
        l -= 1
        
        while nl > l:
            nl -= 1
            add(A[nl])
        while nr < r:
            add(A[nr])
            nr += 1
        while nl < l:
            rem(A[nl])
            nl += 1
        while nr > r:
            nr -= 1
            rem(A[nr])
        
        answers[i] = ans
    return answers

if sys.argv[-1] == 'ONLINE_JUDGE':
    import numba
    from numba.pycc import CC
    i4 = numba.int32
    i8 = numba.int64
    cc = CC('my_module')

    def cc_export(f, signature):
        cc.export(f.__name__, signature)(f)
        return numba.njit(f)

    Mo_argsort = cc_export(Mo_argsort, (i8[:,:],))
    main = cc_export(main, (i8[:], i8[:, :]))
    cc.compile()

from my_module import main

N, Q = map(int, readline().split())
A = np.array(readline().split(), np.int64)
LR = np.array(read().split(), np.int64).reshape(Q, 2)

ans = main(A, LR)
print('\n'.join(map(str, ans.tolist())))

Solution (Python):
import sys
input = sys.stdin.readline


class BIT:
    def __init__(self, n):
        self.array = [0] * (n + 1)
        self.size = n

    def sum(self, i):
        s = 0
        tmp = i
        while tmp > 0:
            s += self.array[tmp]
            tmp -= tmp & -tmp
        return s

    def add(self, i, x):
        tmp = i + 1
        while tmp <= self.size:
            self.array[tmp] += x
            tmp += tmp & -tmp


def main():
    n, q = map(int, input().split())
    *C, = map(lambda x: int(x) - 1, input().split())
    P = [0] * n
    N = [None] * n
    for i in range(n)[::-1]:
        if P[C[i]]:
            N[i] = P[C[i]]
        P[C[i]] = i
    F = [0] * n
    B = BIT(n)
    for i in range(n):
        if F[C[i]] == 0:
            B.add(i, 1)
            F[C[i]] = 1
    XY = [tuple(map(int, input().split())) for j in range(q)]
    ids = list(range(q))
    ids.sort(key=lambda j: XY[j][0])
    a = 0
    lst = [0] * q
    for j in ids:
        x, y = XY[j]
        for i in range(a, x - 1):
            if N[i]:
                B.add(N[i], 1)
        a = x - 1
        lst[j] = B.sum(y) - B.sum(x - 1)
    print(*lst, sep="\n")


main()

Solution (Python):
n, q = map(int, input().split())
bit = [0] * (n + 1)


def fenwick_add(x, w):
    while x <= n:
        bit[x] += w
        x += x & -x


def fenwick_sum(x):
    sm = 0
    while x > 0:
        sm += bit[x]
        x -= x & -x
    return sm


c = list(map(int, input().split()))
p = [-1] * (n + 1)
ps = [[] for _ in range(n + 1)]
for i, v in enumerate(c):
    l = p[v]
    if l != -1:
        ps[l].append(i)
    p[v] = i

qs = [[] for _ in range(n + 1)]
for i in range(q):
    l, r = map(int, input().split())
    qs[l - 1].append([r - 1, i])

ans = [0] * q
for i in range(n - 1, -1, -1):
    for v in ps[i]:
        fenwick_add(v, 1)
    for v in qs[i]:
        r, qi = v
        ans[qi] = r - i + 1 - fenwick_sum(r)
print(*ans, sep="\n")

Solution (Python):
import sys
input = sys.stdin.readline


class Bit:
    def __init__(self, n):
        self.size = n
        self.tree = [0 for _ in range(n + 2)]
 
    def sum(self, i):
        s = 0
        while i > 0:
            s += self.tree[i]
            i -= i & -i
        return s
 
    def add(self, i, x):
        while i <= self.size:
            self.tree[i] += x
            i += i & -i


n, q = map(int, input().split())
c = list(map(int, input().split()))

rli = []
for i in range(q):
    l, r = map(int, input().split())
    rli.append((r, l, i))
rli.sort(key=lambda x: x[0])

last = [-1 for _ in range(n + 1)]

bit = Bit(n)
ans = [-1 for _ in range(q)]
cur = 1
for r, l, i in rli:
    for j in range(cur, r + 1):
        if last[c[j - 1]] != -1:
            bit.add(last[c[j - 1]], -1)
        last[c[j - 1]] = j
        bit.add(j, 1)
    cur = r + 1
    ans[i] = bit.sum(r) - bit.sum(l - 1)
print(*ans, sep="\n")

Solution (Python):
import sys
input=sys.stdin.readline

def segfunc(x,y):
    return x+y

def init(init_val):
    
    for i in range(n):
        seg[i+num-1]=init_val[i]
    
    for i in range(num-2,-1,-1):
        seg[i]=segfunc(seg[2*i+1],seg[2*i+2])
    
def update(k,x):
    k+=num-1
    seg[k]=x
    while k+1:
        k=(k-1)//2
        seg[k]=segfunc(seg[k*2+1],seg[k*2+2])

def query(p,q):
    if q<=p:
        return ide_ele
    p+=num-1
    q+=num-2
    res=ide_ele
    while q-p>1:
        if p&1==0:
            res=segfunc(res,seg[p])
        if q&1==1:
            res=segfunc(res,seg[q])
            q-=1
        p=p//2
        q=(q-1)//2
    if p==q:
        res=segfunc(res,seg[p])
    else:
        res=segfunc(segfunc(res,seg[p]),seg[q])
    return res

ide_ele=0
n,q=map(int,input().split())
num=2**(n-1).bit_length()
seg=[ide_ele]*2*num
c=list(map(int,input().split()))
lr=[]
for i in range(q):
    lr.append(list(map(int,input().split())) + [i])
lr.sort(key=lambda x: x[1])
ans=[0]*q
ll=0
lastc=[-1]*(n+1)
for l,r,ind in lr:
    l-=1
    r-=1
    while ll<=r:
        if lastc[c[ll]]==-1:
            lastc[c[ll]]=ll
            update(ll,1)
        else:
            update(lastc[c[ll]],0)
            lastc[c[ll]]=ll
            update(lastc[c[ll]],1)
        ll+=1
    ans[ind]=query(l,r+1)
for i in ans:
    print(i)

Solution (Python):
I = [int(_) for _ in open(0).read().split()]
N, Q = I[:2]
C = [0] + I[2:2 + N]
LR = I[2 + N:]
L, R = LR[::2], LR[1::2]


class BinaryIndexedTree():
    def __init__(self, n):
        """
        constructs binary indexed tree

        Parameters
        ----------
        n : int
            maximum index value
        """
        self.n = n
        self.dat = [0] * (n + 1)

    def sum(self, i):
        """
        returns the sum of [1, i]

        Parameters
        ----------
        i : int
            right end of the interval
        """
        s = 0
        while i:
            s += self.dat[i]
            i -= i & -i
        return s

    def add(self, i, x):
        """
        adds x to i-th element

        Parameters
        ----------
        i : int
            index
        x : int
            additional value
        """
        while i <= self.n:
            self.dat[i] += x
            i += i & -i


BIT = BinaryIndexedTree(500010)

arr = [5 * 10**5 + 4] * (5 * 10**5 + 5)
RLI = sorted(r * (2 ** 40) + l * (2 ** 20) + i for r, l, i in zip(R, L, range(Q)))
ans = [None] * Q
j = 0
for rli in RLI:
    r, li = divmod(rli, 2 ** 40)
    l, i = divmod(li, 2 ** 20)
    for j in range(j + 1, r + 1):
        BIT.add(arr[C[j]], -1)
        arr[C[j]] = j
        BIT.add(j, 1)
    ans[i] = BIT.sum(r) - BIT.sum(l - 1)
print('\n'.join(map(str, ans)))

Solution (Python):
def add(i,x):
    global BIT
    i+=1
    while i<=n:
        BIT[i] += x
        i += i&(-i)
        
def bitsum(i):
    x = 0
    i+=1
    while i>0:
        x += BIT[i]
        i -= i&(-i)
    return x

def sums(l,r):
    return bitsum(r-1)-bitsum(l-1)

n,q = map(int,input().split())
c = list(map(int,input().split()))
pi = [-1]*(n+1)
ps = [[] for _ in range(n)]
qs = [[] for _ in range(n)]
for i in range(n):
    l = pi[c[i]]
    if l!=-1:
        ps[l].append(i)
    pi[c[i]] = i
for i in range(q):
    l,r = map(int,input().split())
    l,r = l-1,r-1
    qs[l].append((r,i))
BIT = [0]*(n+1)
ans = [None]*q
for x in range(n-1,-1,-1):
    for y in ps[x]:
        add(y,1)
    for r,i in qs[x]:
        ans[i] = r-x+1-bitsum(r)

for i in ans:
    print(i)

Solution (Python):
import sys,bisect,string,math,time,functools,random,fractions
from heapq import heappush,heappop,heapify
from collections import deque,defaultdict,Counter
from itertools import permutations,combinations,groupby
rep=range;R=range
def Golf():n,*t=map(int,open(0).read().split())
def I():return int(input())
def S_():return input()
def IS():return input().split()
def LS():return [i for i in input().split()]
def MI():return map(int,input().split())
def LI():return [int(i) for i in input().split()]
def LI_():return [int(i)-1 for i in input().split()]
def NI(n):return [int(input()) for i in range(n)]
def NI_(n):return [int(input())-1 for i in range(n)]
def StoLI():return [ord(i)-97 for i in input()]
def ItoS(n):return chr(n+97)
def LtoS(ls):return ''.join([chr(i+97) for i in ls])
def Ra():return map(int,open(0).read().split())
def GI(V,E,ls=None,Directed=False,index=1):
    org_inp=[];g=[[] for i in range(V)]
    FromStdin=True if ls==None else False
    for i in range(E):
        if FromStdin:
            inp=LI()
            org_inp.append(inp)
        else:
            inp=ls[i]
        if len(inp)==2:
            a,b=inp;c=1
        else:
            a,b,c=inp
        if index==1:a-=1;b-=1
        aa=(a,c);bb=(b,c);g[a].append(bb)
        if not Directed:g[b].append(aa)
    return g,org_inp
def GGI(h,w,search=None,replacement_of_found='.',mp_def={'
    
    mp=[boundary]*(w+2);found={}
    for i in R(h):
        s=input()
        for char in search:
            if char in s:
                found[char]=((i+1)*(w+2)+s.index(char)+1)
                mp_def[char]=mp_def[replacement_of_found]
        mp+=[boundary]+[mp_def[j] for j in s]+[boundary]
    mp+=[boundary]*(w+2)
    return h+2,w+2,mp,found
def TI(n):return GI(n,n-1)
def accum(ls):
    rt=[0]
    for i in ls:rt+=[rt[-1]+i]
    return rt
def bit_combination(n,base=2):
    rt=[]
    for tb in R(base**n):s=[tb//(base**bt)%base for bt in R(n)];rt+=[s]
    return rt
def gcd(x,y):
    if y==0:return x
    if x%y==0:return y
    while x%y!=0:x,y=y,x%y
    return y
def YN(x):print(['NO','YES'][x])
def Yn(x):print(['No','Yes'][x])
def show(*inp,end='\n'):
    if show_flg:print(*inp,end=end)

mo=10**9+7
inf=float('inf')
FourNb=[(-1,0),(1,0),(0,1),(0,-1)];EightNb=[(-1,0),(1,0),(0,1),(0,-1),(1,1),(-1,-1),(1,-1),(-1,1)];compas=dict(zip('WENS',FourNb));cursol=dict(zip('LRUD',FourNb))
l_alp=string.ascii_lowercase
sys.setrecursionlimit(10**9)
read=sys.stdin.buffer.read;readline=sys.stdin.buffer.readline;input=lambda:sys.stdin.readline().rstrip()













class Bit: 
    def __init__(self,n,init=None):
        self.size=n
        self.m=self.size.bit_length()
        self.arr=[0]*(2**self.m+1)
        self.el=[0]*(2**self.m+1)
        if init!=None:
            for i in range(len(init)):
                self.add(i,init[i])
                self.el[i]=init[i]

    def __str__(self):
        a=[self.sum(i+1)-self.sum(i) for i in range(self.size)]
        return str(a)
        
    def add(self,i,x):
        if not 0<i<=self.size:
            raise IndexError('BIT add(x): index out of range. '+str(i)+' not in [0,'+str(self.size)+']')
        self.el[i]+=x
        while i<=self.size:
            self.arr[i]+=x
            i+=i&(-i)
        return
    
    def sum(self,i):
        if not 0<=i<=self.size:
            raise IndexError('BIT sum(x): index out of range. '+str(i)+' not in [0,'+str(self.size)+']')
        rt=0
        while i>0:
            rt+=self.arr[i]
            i-=i&(-i)
        return rt

    def __getitem__(self,key):
        if type(key) is slice:
            a=0 if key.start==None else key.start
            b=self.size if key.stop==None else key.stop
            if key.step!=None:return NotImplemented
            return [self.sum(b)-self.sum(a)]
        else:
            return self.el[key]

    def __setitem__(self,key,value):
        self.add(key,value+self.sum(key)-self.sum(key+1))

    def l_bound(self,w):
        if w<=0:
            return 0
        x=0
        k=2**self.m
        while k>0:
            if x+k<=self.size and self.arr[x+k]<w:
                w-=self.arr[x+k]
                x+=k
            k>>=1
        return x+1
        
    def u_bound(self,w):
        if w<=0:
            return 0
        x=0
        k=2**self.m
        while k>0:
            if x+k<=self.size and self.arr[x+k]<=w:
                w-=self.arr[x+k]
                x+=k
            k>>=1
        return x+1
        
class Bit0(Bit): 
    def add(self,j,x):
        super().add(j+1,x)
    def l_bound(self,w):
        return max(super().l_bound(w)-1,0)
    def u_bound(self,w):
        return max(super().u_bound(w)-1,0)

class Multiset(Bit0):
    def __init__(self,max_v):
        super().__init__(max_v)
    def insert(self,x):
        super().add(x,1)
    def find(self,x):
        return super().l_bound(super().sum(x))
    def __str__(self):
        return str(self.arr)

def compress(L):
    dc={v:i for i,v in enumerate(sorted(set(L)))}
    return [dc[i] for i in L]

show_flg=False
show_flg=True

ans=0

n,Q=LI()
c=LI_()

q=[(i,LI())for i in range(Q)]

q.sort(key=lambda x:x[1][1])

bt=Bit0(-~n)
lst=[-1]*-~n

ans=[0]*Q
R=0
for j,(l,r) in q:
    while R<r:
        col=c[R]
        if lst[col]!=-1:
            bt.add(lst[col],-1)
        lst[col]=R
        bt.add(lst[col],1)
        R+=1
    ans[j]=bt.sum(r+1)-bt.sum(l-1)
for i in ans:
    print(i)

Solution (Python):
import sys,bisect,string,math,time,functools,random,fractions
from heapq import heappush,heappop,heapify
from collections import deque,defaultdict,Counter
from itertools import permutations,combinations,groupby
rep=range;R=range
def Golf():n,*t=map(int,open(0).read().split())
def I():return int(input())
def S_():return input()
def IS():return input().split()
def LS():return [i for i in input().split()]
def MI():return map(int,input().split())
def LI():return [int(i) for i in input().split()]
def LI_():return [int(i)-1 for i in input().split()]
def NI(n):return [int(input()) for i in range(n)]
def NI_(n):return [int(input())-1 for i in range(n)]
def StoLI():return [ord(i)-97 for i in input()]
def ItoS(n):return chr(n+97)
def LtoS(ls):return ''.join([chr(i+97) for i in ls])
def Ra():return map(int,open(0).read().split())
def GI(V,E,ls=None,Directed=False,index=1):
    org_inp=[];g=[[] for i in range(V)]
    FromStdin=True if ls==None else False
    for i in range(E):
        if FromStdin:
            inp=LI()
            org_inp.append(inp)
        else:
            inp=ls[i]
        if len(inp)==2:
            a,b=inp;c=1
        else:
            a,b,c=inp
        if index==1:a-=1;b-=1
        aa=(a,c);bb=(b,c);g[a].append(bb)
        if not Directed:g[b].append(aa)
    return g,org_inp
def GGI(h,w,search=None,replacement_of_found='.',mp_def={'
    
    mp=[boundary]*(w+2);found={}
    for i in R(h):
        s=input()
        for char in search:
            if char in s:
                found[char]=((i+1)*(w+2)+s.index(char)+1)
                mp_def[char]=mp_def[replacement_of_found]
        mp+=[boundary]+[mp_def[j] for j in s]+[boundary]
    mp+=[boundary]*(w+2)
    return h+2,w+2,mp,found
def TI(n):return GI(n,n-1)
def accum(ls):
    rt=[0]
    for i in ls:rt+=[rt[-1]+i]
    return rt
def bit_combination(n,base=2):
    rt=[]
    for tb in R(base**n):s=[tb//(base**bt)%base for bt in R(n)];rt+=[s]
    return rt
def gcd(x,y):
    if y==0:return x
    if x%y==0:return y
    while x%y!=0:x,y=y,x%y
    return y
def YN(x):print(['NO','YES'][x])
def Yn(x):print(['No','Yes'][x])
def show(*inp,end='\n'):
    if show_flg:print(*inp,end=end)

mo=10**9+7
inf=float('inf')
FourNb=[(-1,0),(1,0),(0,1),(0,-1)];EightNb=[(-1,0),(1,0),(0,1),(0,-1),(1,1),(-1,-1),(1,-1),(-1,1)];compas=dict(zip('WENS',FourNb));cursol=dict(zip('LRUD',FourNb))
l_alp=string.ascii_lowercase

read=sys.stdin.buffer.read;readline=sys.stdin.buffer.readline;input=lambda:sys.stdin.readline().rstrip()













class Bit: 
    def __init__(self,n,init=None):
        self.size=n
        self.m=self.size.bit_length()
        self.arr=[0]*(2**self.m+1)
        self.el=[0]*(2**self.m+1)
        if init!=None:
            for i in range(len(init)):
                self.add(i,init[i])
                self.el[i]=init[i]

    def __str__(self):
        a=[self.sum(i+1)-self.sum(i) for i in range(self.size)]
        return str(a)
        
    def add(self,i,x):
        if not 0<i<=self.size:
            raise IndexError('BIT add(x): index out of range. '+str(i)+' not in [0,'+str(self.size)+']')
        self.el[i]+=x
        while i<=self.size:
            self.arr[i]+=x
            i+=i&(-i)
        return
    
    def sum(self,i):
        if not 0<=i<=self.size:
            raise IndexError('BIT sum(x): index out of range. '+str(i)+' not in [0,'+str(self.size)+']')
        rt=0
        while i>0:
            rt+=self.arr[i]
            i-=i&(-i)
        return rt

    def __getitem__(self,key):
        if type(key) is slice:
            a=0 if key.start==None else key.start
            b=self.size if key.stop==None else key.stop
            if key.step!=None:return NotImplemented
            return [self.sum(b)-self.sum(a)]
        else:
            return self.el[key]

    def __setitem__(self,key,value):
        self.add(key,value+self.sum(key)-self.sum(key+1))

    def l_bound(self,w):
        if w<=0:
            return 0
        x=0
        k=2**self.m
        while k>0:
            if x+k<=self.size and self.arr[x+k]<w:
                w-=self.arr[x+k]
                x+=k
            k>>=1
        return x+1
        
    def u_bound(self,w):
        if w<=0:
            return 0
        x=0
        k=2**self.m
        while k>0:
            if x+k<=self.size and self.arr[x+k]<=w:
                w-=self.arr[x+k]
                x+=k
            k>>=1
        return x+1
        
class Bit0(Bit): 
    def add(self,j,x):
        super().add(j+1,x)
    def l_bound(self,w):
        return max(super().l_bound(w)-1,0)
    def u_bound(self,w):
        return max(super().u_bound(w)-1,0)

class Multiset(Bit0):
    def __init__(self,max_v):
        super().__init__(max_v)
    def insert(self,x):
        super().add(x,1)
    def find(self,x):
        return super().l_bound(super().sum(x))
    def __str__(self):
        return str(self.arr)

def compress(L):
    dc={v:i for i,v in enumerate(sorted(set(L)))}
    return [dc[i] for i in L]


show_flg=False
show_flg=True

ans=0

n,Q=LI()
c=LI_()

q=[(i,LI())for i in range(Q)]

q.sort(key=lambda x:x[1][1])

bt=Bit0(-~n)
lst=[-1]*-~n

ans=[0]*Q
R=0
for j,(l,r) in q:
    while R<r:
        col=c[R]
        if lst[col]!=-1:
            bt[lst[col]]=0
        lst[col]=R
        bt[lst[col]]=1
        R+=1
    ans[j]=sum(bt[l-1:r])
for i in ans:
    print(i)