Buggy python submission (verdict: Runtime Error):
n = int(input())
s = input()

candidates = [0 for i in range(10 ** 3)]

count = 0
for i in range(1000):
    tmp_pass = f'{i:03}'

    index_0 = s.find(tmp_pass[0])
    if index_0 != -1 and index_0 < len(s) - 2:
        s_1 = s[index_0 + 1:]
        index_1 = s_1.find(tmp_pass[1])
        if index_1 != -1 and index_1 < len(s_1) - 1:
            s_2 = s_1[index_1 + 1:]
            # print(tmp_pass)
            # print(s_2)
            # index_2 = s_2.find(tmp_pass[2])
            # print(index_2)
            if s_2.find(tmp_pass[2]) != -1:
                count += 1

print(count)


Fixed submission:
n = int(input())
s = input()

candidates = [0 for i in range(10 ** 3)]

count = 0
for i in range(1000):
    tmp_pass = '{:03}'.format(i)

    index_0 = s.find(tmp_pass[0])
    if index_0 != -1 and index_0 < len(s) - 2:
        s_1 = s[index_0 + 1:]
        index_1 = s_1.find(tmp_pass[1])
        if index_1 != -1 and index_1 < len(s_1) - 1:
            s_2 = s_1[index_1 + 1:]
            # print(tmp_pass)
            # print(s_2)
            # index_2 = s_2.find(tmp_pass[2])
            # print(index_2)
            if s_2.find(tmp_pass[2]) != -1:
                count += 1

print(count)

Buggy python submission (verdict: Runtime Error):
n = int(input())
s = input()

candidates = [0 for i in range(10 ** 3)]

count = 0
for i in range(1000):
    tmp_pass = f'{i:03}'

    index_0 = s.find(tmp_pass[0])
    if index_0 != -1 and index_0 < len(s) - 2:
        s_1 = s[index_0 + 1:]
        index_1 = s_1.find(tmp_pass[1])
        if index_1 != -1 and index_1 < len(s_1) - 1:
            s_2 = s_1[index_1 + 1:]
            # print(tmp_pass)
            # print(s_2)
            # index_2 = s_2.find(tmp_pass[2])
            # print(index_2)
            if s_2.find(tmp_pass[2]) != -1:
                count += 1

print(count)


Fixed submission:
n = int(input())
s = input()

candidates = [0 for i in range(10 ** 3)]

count = 0
for i in range(1000):
    tmp_pass = '{:03}'.format(i)

    index_0 = s.find(tmp_pass[0])
    if index_0 != -1 and index_0 < len(s) - 2:
        s_1 = s[index_0 + 1:]
        index_1 = s_1.find(tmp_pass[1])
        if index_1 != -1 and index_1 < len(s_1) - 1:
            s_2 = s_1[index_1 + 1:]
            # print(tmp_pass)
            # print(s_2)
            # index_2 = s_2.find(tmp_pass[2])
            # print(index_2)
            if s_2.find(tmp_pass[2]) != -1:
                count += 1

print(count)

Buggy python submission (verdict: Time Limit Exceeded):
n = int(input())
s = input()

pass_set = set([])
for i in range(n):
    for j in range(i + 1, n):
        for k in range(j + 1, n):
            pass_set.add(s[i] + s[j] + s[k])

print(len(pass_set))


Fixed submission:
n = int(input())
s = input()

candidates = [0 for i in range(10 ** 3)]

count = 0
for i in range(1000):
    tmp_pass = '{:03}'.format(i)

    index_0 = s.find(tmp_pass[0])
    if index_0 != -1 and index_0 < len(s) - 2:
        s_1 = s[index_0 + 1:]
        index_1 = s_1.find(tmp_pass[1])
        if index_1 != -1 and index_1 < len(s_1) - 1:
            s_2 = s_1[index_1 + 1:]
            # print(tmp_pass)
            # print(s_2)
            # index_2 = s_2.find(tmp_pass[2])
            # print(index_2)
            if s_2.find(tmp_pass[2]) != -1:
                count += 1

print(count)