Buggy python submission (verdict: Time Limit Exceeded):
import sys, re
from collections import deque, defaultdict, Counter
from math import ceil, sqrt, hypot, factorial, pi, sin, cos, radians, gcd
from itertools import accumulate, permutations, combinations, product, groupby, combinations_with_replacement
from operator import itemgetter, mul
from copy import deepcopy
from string import ascii_lowercase, ascii_uppercase, digits
from bisect import bisect, bisect_left
from heapq import heappush, heappop
from functools import reduce
def input(): return sys.stdin.readline().strip()
def INT(): return int(input())
def MAP(): return map(int, input().split())
def LIST(): return list(map(int, input().split()))
def ZIP(n): return zip(*(MAP() for _ in range(n)))
sys.setrecursionlimit(10 ** 9)
INF = float('inf')
mod = 10 ** 9 + 7

class Bit:
    def __init__(self, n):
        self.size = n
        self.tree = [0] * (n + 1)
    def sum(self, i):  # 区間 [1, i]の和
        s = 0
        while i > 0:
            s += self.tree[i]
            i -= i & -i
        return s
    def add(self, i, x):  # iにxを加算
        while i <= self.size:
            self.tree[i] += x
            i += i & -i  
    def pos(self, idx):  # idxの値を取得
        return self.sum(idx) - self.sum(idx-1)
    def lower_bound(self, w):  # w以上の値を持つ最小のidxを検索
        if w <= 0:
            return 0
        idx = 0
        k = 1
        while k*2 <= self.size:
            k *= 2
        while k > 0:
            if idx+k <= self.size and self.tree[idx+k] < w:
                w -= self.tree[idx+k]
                idx += k
            k //= 2
        return idx+1

N, Q = MAP()
c = LIST()
ps = [[] for _ in range(N+1)]
qs = [[] for _ in range(N+1)]
for i in range(Q):
    l, r = MAP()
    qs[l].append((r, i))

checked = [-1]*(N+1)
for i, x in enumerate(c):
    if checked[x] != -1:
        ps[checked[x]].append(i+1)
    checked[x] = i+1

ans = [-1]*Q
bit = Bit(N)

for x in range(N, 0, -1):
    for y in ps[x]:
        bit.add(y, 1)
    for r, i in qs[x]:
        ans[i] = r-x+1-bit.sum(r)

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


Fixed submission:
import sys, re
from collections import deque, defaultdict, Counter
from math import ceil, sqrt, hypot, factorial, pi, sin, cos, radians, gcd
from itertools import accumulate, permutations, combinations, product, groupby, combinations_with_replacement
from operator import itemgetter, mul
from copy import deepcopy
from string import ascii_lowercase, ascii_uppercase, digits
from bisect import bisect, bisect_left
from heapq import heappush, heappop
from functools import reduce
def input(): return sys.stdin.readline().strip()
def INT(): return int(input())
def MAP(): return map(int, input().split())
def LIST(): return list(map(int, input().split()))
def ZIP(n): return zip(*(MAP() for _ in range(n)))
sys.setrecursionlimit(10 ** 9)
INF = float('inf')
mod = 10 ** 9 + 7

class Bit:
    def __init__(self, n):
        self.size = n
        self.tree = [0] * (n + 1)
    def sum(self, i):  # 区間 [1, i]の和
        s = 0
        while i > 0:
            s += self.tree[i]
            i -= i & -i
        return s
    def add(self, i, x):  # iにxを加算
        while i <= self.size:
            self.tree[i] += x
            i += i & -i  
    def pos(self, idx):  # idxの値を取得
        return self.sum(idx) - self.sum(idx-1)
    def lower_bound(self, w):  # w以上の値を持つ最小のidxを検索
        if w <= 0:
            return 0
        idx = 0
        k = 1
        while k*2 <= self.size:
            k *= 2
        while k > 0:
            if idx+k <= self.size and self.tree[idx+k] < w:
                w -= self.tree[idx+k]
                idx += k
            k //= 2
        return idx+1

N, Q = MAP()
c = LIST()
ilr = [[i]+LIST() for i, _ in enumerate(range(Q))]
ilr.sort(key=lambda x:x[2])
bit = Bit(N)
rtmp = ilr[0][2]
last = [None]*(N+1)
for i in range(rtmp):
    last[c[i]] = i+1
for i in range(1, N+1):
    if last[i]:
        bit.add(last[i], 1)

ans = [0]*Q
for i, l, r in ilr:
    if rtmp < r:
        for j in range(rtmp+1, r+1):
            if last[c[j-1]]:
                bit.add(last[c[j-1]], -1)
            last[c[j-1]] = j
            bit.add(j, 1)
        rtmp = r
    ans[i] = bit.sum(r)-bit.sum(l-1)

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

Buggy python submission (verdict: Runtime Error):
import sys, re
from collections import deque, defaultdict, Counter
from math import ceil, sqrt, hypot, factorial, pi, sin, cos, radians, gcd
from itertools import accumulate, permutations, combinations, product, groupby, combinations_with_replacement
from operator import itemgetter, mul
from copy import deepcopy
from string import ascii_lowercase, ascii_uppercase, digits
from bisect import bisect, bisect_left
from heapq import heappush, heappop
from functools import reduce
def input(): return sys.stdin.readline().strip()
def INT(): return int(input())
def MAP(): return map(int, input().split())
def LIST(): return list(map(int, input().split()))
def ZIP(n): return zip(*(MAP() for _ in range(n)))
sys.setrecursionlimit(10 ** 9)
INF = float('inf')
mod = 10 ** 9 + 7

class Bit:
    def __init__(self, n):
        self.size = n
        self.tree = [0] * (n + 1)
    def sum(self, i):  # 区間 [1, i]の和
        s = 0
        while i > 0:
            s += self.tree[i]
            i -= i & -i
        return s
    def add(self, i, x):  # iにxを加算
        while i <= self.size:
            self.tree[i] += x
            i += i & -i  
    def pos(self, idx):  # idxの値を取得
        return self.sum(idx) - self.sum(idx-1)
    def lower_bound(self, w):  # w以上の値を持つ最小のidxを検索
        if w <= 0:
            return 0
        idx = 0
        k = 1
        while k*2 <= self.size:
            k *= 2
        while k > 0:
            if idx+k <= self.size and self.tree[idx+k] < w:
                w -= self.tree[idx+k]
                idx += k
            k //= 2
        return idx+1

N, Q = MAP()
c = LIST()
ps = [[] for _ in range(N+1)]
qs = [[] for _ in range(N+1)]
for i in range(Q):
    l, r = MAP()
    qs[l].append((r, i))

checked = [-1]*N
for i, x in enumerate(c):
    if checked[x] != -1:
        ps[checked[x]].append(i+1)
    checked[x] = i+1

ans = [-1]*Q
bit = Bit(N)

for x in range(N, 0, -1):
    for y in ps[x]:
        bit.add(y, 1)
    for r, i in qs[x]:
        ans[i] = r-x+1-bit.sum(r)

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


Fixed submission:
import sys, re
from collections import deque, defaultdict, Counter
from math import ceil, sqrt, hypot, factorial, pi, sin, cos, radians, gcd
from itertools import accumulate, permutations, combinations, product, groupby, combinations_with_replacement
from operator import itemgetter, mul
from copy import deepcopy
from string import ascii_lowercase, ascii_uppercase, digits
from bisect import bisect, bisect_left
from heapq import heappush, heappop
from functools import reduce
def input(): return sys.stdin.readline().strip()
def INT(): return int(input())
def MAP(): return map(int, input().split())
def LIST(): return list(map(int, input().split()))
def ZIP(n): return zip(*(MAP() for _ in range(n)))
sys.setrecursionlimit(10 ** 9)
INF = float('inf')
mod = 10 ** 9 + 7

class Bit:
    def __init__(self, n):
        self.size = n
        self.tree = [0] * (n + 1)
    def sum(self, i):  # 区間 [1, i]の和
        s = 0
        while i > 0:
            s += self.tree[i]
            i -= i & -i
        return s
    def add(self, i, x):  # iにxを加算
        while i <= self.size:
            self.tree[i] += x
            i += i & -i  
    def pos(self, idx):  # idxの値を取得
        return self.sum(idx) - self.sum(idx-1)
    def lower_bound(self, w):  # w以上の値を持つ最小のidxを検索
        if w <= 0:
            return 0
        idx = 0
        k = 1
        while k*2 <= self.size:
            k *= 2
        while k > 0:
            if idx+k <= self.size and self.tree[idx+k] < w:
                w -= self.tree[idx+k]
                idx += k
            k //= 2
        return idx+1

N, Q = MAP()
c = LIST()
ilr = [[i]+LIST() for i, _ in enumerate(range(Q))]
ilr.sort(key=lambda x:x[2])
bit = Bit(N)
rtmp = ilr[0][2]
last = [None]*(N+1)
for i in range(rtmp):
    last[c[i]] = i+1
for i in range(1, N+1):
    if last[i]:
        bit.add(last[i], 1)

ans = [0]*Q
for i, l, r in ilr:
    if rtmp < r:
        for j in range(rtmp+1, r+1):
            if last[c[j-1]]:
                bit.add(last[c[j-1]], -1)
            last[c[j-1]] = j
            bit.add(j, 1)
        rtmp = r
    ans[i] = bit.sum(r)-bit.sum(l-1)

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

Buggy python submission (verdict: Runtime Error):
import sys, re
from collections import deque, defaultdict, Counter
from math import ceil, sqrt, hypot, factorial, pi, sin, cos, radians, gcd
from itertools import accumulate, permutations, combinations, product, groupby, combinations_with_replacement
from operator import itemgetter, mul
from copy import deepcopy
from string import ascii_lowercase, ascii_uppercase, digits
from bisect import bisect, bisect_left
from heapq import heappush, heappop
from functools import reduce
def input(): return sys.stdin.readline().strip()
def INT(): return int(input())
def MAP(): return map(int, input().split())
def LIST(): return list(map(int, input().split()))
def ZIP(n): return zip(*(MAP() for _ in range(n)))
sys.setrecursionlimit(10 ** 9)
INF = float('inf')
mod = 10 ** 9 + 7

class Bit:
    def __init__(self, n):
        self.size = n
        self.tree = [0] * (n + 1)
    def sum(self, i):  # 区間 [1, i]の和
        s = 0
        while i > 0:
            s += self.tree[i]
            i -= i & -i
        return s
    def add(self, i, x):  # iにxを加算
        while i <= self.size:
            self.tree[i] += x
            i += i & -i  
    def pos(self, idx):  # idxの値を取得
        return self.sum(idx) - self.sum(idx-1)
    def lower_bound(self, w):  # w以上の値を持つ最小のidxを検索
        if w <= 0:
            return 0
        idx = 0
        k = 1
        while k*2 <= self.size:
            k *= 2
        while k > 0:
            if idx+k <= self.size and self.tree[idx+k] < w:
                w -= self.tree[idx+k]
                idx += k
            k //= 2
        return idx+1

N, Q = MAP()
c = LIST()
ilr = [[i]+LIST() for i, _ in enumerate(range(Q))]
ranges = []
checked = [0]*N
for i, x in enumerate(c):
    if checked[x]:
        ranges.append([-1, checked[x], i+1])
    checked[x] = i+1

points = ranges+ilr
points.sort(key=lambda x:-x[1])

ans = [0]*Q
bit = Bit(N)
for i, l, r in points:
    if i == -1:  # 追加
        bit.add(r, 1)
    else:  # 判定
        ans[i] = r-l+1-bit.sum(r)
print(*ans, sep="\n")


Fixed submission:
import sys, re
from collections import deque, defaultdict, Counter
from math import ceil, sqrt, hypot, factorial, pi, sin, cos, radians, gcd
from itertools import accumulate, permutations, combinations, product, groupby, combinations_with_replacement
from operator import itemgetter, mul
from copy import deepcopy
from string import ascii_lowercase, ascii_uppercase, digits
from bisect import bisect, bisect_left
from heapq import heappush, heappop
from functools import reduce
def input(): return sys.stdin.readline().strip()
def INT(): return int(input())
def MAP(): return map(int, input().split())
def LIST(): return list(map(int, input().split()))
def ZIP(n): return zip(*(MAP() for _ in range(n)))
sys.setrecursionlimit(10 ** 9)
INF = float('inf')
mod = 10 ** 9 + 7

class Bit:
    def __init__(self, n):
        self.size = n
        self.tree = [0] * (n + 1)
    def sum(self, i):  # 区間 [1, i]の和
        s = 0
        while i > 0:
            s += self.tree[i]
            i -= i & -i
        return s
    def add(self, i, x):  # iにxを加算
        while i <= self.size:
            self.tree[i] += x
            i += i & -i  
    def pos(self, idx):  # idxの値を取得
        return self.sum(idx) - self.sum(idx-1)
    def lower_bound(self, w):  # w以上の値を持つ最小のidxを検索
        if w <= 0:
            return 0
        idx = 0
        k = 1
        while k*2 <= self.size:
            k *= 2
        while k > 0:
            if idx+k <= self.size and self.tree[idx+k] < w:
                w -= self.tree[idx+k]
                idx += k
            k //= 2
        return idx+1

N, Q = MAP()
c = LIST()
ilr = [[i]+LIST() for i, _ in enumerate(range(Q))]
ilr.sort(key=lambda x:x[2])
bit = Bit(N)
rtmp = ilr[0][2]
last = [None]*(N+1)
for i in range(rtmp):
    last[c[i]] = i+1
for i in range(1, N+1):
    if last[i]:
        bit.add(last[i], 1)

ans = [0]*Q
for i, l, r in ilr:
    if rtmp < r:
        for j in range(rtmp+1, r+1):
            if last[c[j-1]]:
                bit.add(last[c[j-1]], -1)
            last[c[j-1]] = j
            bit.add(j, 1)
        rtmp = r
    ans[i] = bit.sum(r)-bit.sum(l-1)

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

Buggy python submission (verdict: Time Limit Exceeded):
import sys, re
from collections import deque, defaultdict, Counter
from math import ceil, sqrt, hypot, factorial, pi, sin, cos, radians, gcd
from itertools import accumulate, permutations, combinations, product, groupby, combinations_with_replacement
from operator import itemgetter, mul
from copy import deepcopy
from string import ascii_lowercase, ascii_uppercase, digits
from bisect import bisect, bisect_left
from heapq import heappush, heappop
from functools import reduce
def input(): return sys.stdin.readline().strip()
def INT(): return int(input())
def MAP(): return map(int, input().split())
def LIST(): return list(map(int, input().split()))
def ZIP(n): return zip(*(MAP() for _ in range(n)))
sys.setrecursionlimit(10 ** 9)
INF = float('inf')
mod = 10 ** 9 + 7

class SegmentTree:
    """Segment Tree (Point Update & Range Query)
    Query
        1. update(i, val): update i-th value(0-indexed) to val
        2. query(low, high): find f(value) in [low, high)
    Complexity
        time complexity: O(log n)
        space complexity: O(n)
    """
    def __init__(self, N, f, default):
        self.N = 1 << (N-1).bit_length()
        self.default = default
        self.f = f
        self.segtree = [self.default] * ((self.N << 1) - 1)
    @classmethod
    def create_from_array(cls, arr, f, default):
        N = len(arr)
        self = cls(N, f, default)
        for i in range(N):
            self.segtree[self.N - 1 + i] = arr[i]
        for i in reversed(range(self.N - 1)):
            self.segtree[i] = self.f(
                self.segtree[(i << 1) + 1], self.segtree[(i << 1) + 2])
        return self
    def update(self, i, val):  # update
        i += self.N - 1
        self.segtree[i] = val
        while i > 0:
            i = (i - 1) >> 1
            self.segtree[i] = self.f(
                self.segtree[(i << 1)+1], self.segtree[(i << 1)+2])
    def query(self, low, high):  # query
        # query [l, r)
        low, high = low + self.N, high + self.N
        ret = self.default
        while low < high:
            if low & 1:
                ret = self.f(ret, self.segtree[low-1])
                low += 1
            if high & 1:
                high -= 1
                ret = self.f(ret, self.segtree[high-1])
            low, high = low >> 1, high >> 1
        return ret
    def get(self, k):  # get k-th value(0-indexed)
        return self.segtree[k+self.N-1]
    def all(self):  # all range query
        return self.segtree[0]

N, Q = MAP()
c = LIST()

segtree = SegmentTree(N+1, lambda x,y:x|y, set())
for i, x in enumerate(c):
    segtree.update(i, set([x]))

ans = [0]*Q
for i in range(Q):
    l, r = MAP()
    ans[i] = len(segtree.query(l-1, r))
print(*ans, sep="\n")


Fixed submission:
import sys, re
from collections import deque, defaultdict, Counter
from math import ceil, sqrt, hypot, factorial, pi, sin, cos, radians, gcd
from itertools import accumulate, permutations, combinations, product, groupby, combinations_with_replacement
from operator import itemgetter, mul
from copy import deepcopy
from string import ascii_lowercase, ascii_uppercase, digits
from bisect import bisect, bisect_left
from heapq import heappush, heappop
from functools import reduce
def input(): return sys.stdin.readline().strip()
def INT(): return int(input())
def MAP(): return map(int, input().split())
def LIST(): return list(map(int, input().split()))
def ZIP(n): return zip(*(MAP() for _ in range(n)))
sys.setrecursionlimit(10 ** 9)
INF = float('inf')
mod = 10 ** 9 + 7

class Bit:
    def __init__(self, n):
        self.size = n
        self.tree = [0] * (n + 1)
    def sum(self, i):  # 区間 [1, i]の和
        s = 0
        while i > 0:
            s += self.tree[i]
            i -= i & -i
        return s
    def add(self, i, x):  # iにxを加算
        while i <= self.size:
            self.tree[i] += x
            i += i & -i  
    def pos(self, idx):  # idxの値を取得
        return self.sum(idx) - self.sum(idx-1)
    def lower_bound(self, w):  # w以上の値を持つ最小のidxを検索
        if w <= 0:
            return 0
        idx = 0
        k = 1
        while k*2 <= self.size:
            k *= 2
        while k > 0:
            if idx+k <= self.size and self.tree[idx+k] < w:
                w -= self.tree[idx+k]
                idx += k
            k //= 2
        return idx+1

N, Q = MAP()
c = LIST()
ilr = [[i]+LIST() for i, _ in enumerate(range(Q))]
ilr.sort(key=lambda x:x[2])
bit = Bit(N)
rtmp = ilr[0][2]
last = [None]*(N+1)
for i in range(rtmp):
    last[c[i]] = i+1
for i in range(1, N+1):
    if last[i]:
        bit.add(last[i], 1)

ans = [0]*Q
for i, l, r in ilr:
    if rtmp < r:
        for j in range(rtmp+1, r+1):
            if last[c[j-1]]:
                bit.add(last[c[j-1]], -1)
            last[c[j-1]] = j
            bit.add(j, 1)
        rtmp = r
    ans[i] = bit.sum(r)-bit.sum(l-1)

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