Buggy python submission (verdict: Time Limit Exceeded):
N, Q = map(int, input().split())
Color = [0] + list(map(int, input().split()))
Query =[]
for i in range(Q):
    l, r = map(int, input().split())
    Query.append((r, l, i))
Query.sort()
Ans = [0] * Q

BIT = [0] * (N + 1)  # BITを使う


def BIT_query(idx):  # idxまでの合計を返す
    res_sum = 0
    while idx > 0:
        res_sum += BIT[idx]
        idx -= idx&(-idx)
    return res_sum


def BIT_update(idx,x):  # idxにxを足す
    while idx <= N:
        BIT[idx] += x
        idx += idx&(-idx)
    return


cn = max(Color)
Last = [-1] * cn

cnt = 0
for r, l, i in Query:
    while cnt < r:
        cnt += 1
        c = Color[cnt] - 1
        if Last[c] == -1:
            Last[c] = cnt
            BIT_update(cnt, 1)
        else:
            x = Last[c]
            BIT_update(x, -1)
            Last[c] = cnt
            BIT_update(cnt, 1)
    Ans[i] = BIT_query(r) - BIT_query(l-1)

for a in Ans:
    print(a)

Fixed submission:
import sys
input = sys.stdin.buffer.readline

N, Q = map(int, input().split())
Color = [0] + list(map(int, input().split()))
Query =[]
for i in range(Q):
    l, r = map(int, input().split())
    Query.append(r * 10 ** 12 + l * 10 ** 6 + i)
Query.sort()
Ans = [0] * Q

BIT = [0] * (N + 1)  # BITを使う


def BIT_query(idx):  # idxまでの合計を返す
    res_sum = 0
    while idx > 0:
        res_sum += BIT[idx]
        idx -= idx&(-idx)
    return res_sum


def BIT_update(idx,x):  # idxにxを足す
    while idx <= N:
        BIT[idx] += x
        idx += idx&(-idx)
    return


cn = max(Color)
Last = [-1] * cn

cnt = 0
for q in Query:
    r = q // 10 ** 12
    l = (q % 10 ** 12) // 10 ** 6
    i = q % 10 ** 6
    while cnt < r:
        cnt += 1
        c = Color[cnt] - 1
        if Last[c] == -1:
            Last[c] = cnt
            BIT_update(cnt, 1)
        else:
            x = Last[c]
            BIT_update(x, -1)
            Last[c] = cnt
            BIT_update(cnt, 1)
    Ans[i] = BIT_query(r) - BIT_query(l-1)

for a in Ans:
    print(a)

Buggy python submission (verdict: Time Limit Exceeded):
N, Q = map(int, input().split())
C = list(map(int, input().split()))
Query = [tuple(map(int, input().split())) for _ in range(Q)]
Ans = []
D = dict()

Ans.append(D.copy())
for c in C:
    if c in D:
        D[c] += 1
    else:
        D[c] = 1
    Ans.append(D.copy())

for l, r in Query:
    l -= 1
    ans = Ans[r].items() - Ans[l].items()
    print(len(ans))

Fixed submission:
import sys
input = sys.stdin.buffer.readline

N, Q = map(int, input().split())
Color = [0] + list(map(int, input().split()))
Query =[]
for i in range(Q):
    l, r = map(int, input().split())
    Query.append(r * 10 ** 12 + l * 10 ** 6 + i)
Query.sort()
Ans = [0] * Q

BIT = [0] * (N + 1)  # BITを使う


def BIT_query(idx):  # idxまでの合計を返す
    res_sum = 0
    while idx > 0:
        res_sum += BIT[idx]
        idx -= idx&(-idx)
    return res_sum


def BIT_update(idx,x):  # idxにxを足す
    while idx <= N:
        BIT[idx] += x
        idx += idx&(-idx)
    return


cn = max(Color)
Last = [-1] * cn

cnt = 0
for q in Query:
    r = q // 10 ** 12
    l = (q % 10 ** 12) // 10 ** 6
    i = q % 10 ** 6
    while cnt < r:
        cnt += 1
        c = Color[cnt] - 1
        if Last[c] == -1:
            Last[c] = cnt
            BIT_update(cnt, 1)
        else:
            x = Last[c]
            BIT_update(x, -1)
            Last[c] = cnt
            BIT_update(cnt, 1)
    Ans[i] = BIT_query(r) - BIT_query(l-1)

for a in Ans:
    print(a)