HSBC interview prep

DSAEasy

An array holds the numbers from 1 to 8 with exactly one missing: [3, 7, 1, 2, 8, 4, 5]. Using the formula for the sum 1 + 2 + ... + n, which number is missing?

1. 5
2. 9
3. 4
4. 6

This topic is named in a candidate’s interview report: Technology off-campus interview, 2023, on GeeksforGeeks.

DSAMedium

You reverse a singly linked list in place by walking it once with three pointers, prev, curr and next. At each node, what do you do?

1. Save next = curr.next, point curr.next at prev, then move prev to curr and curr to next
2. Swap the node's value with the value at the other end of the list
3. Push every node onto a stack, then pop them all
4. Point curr.next at curr.next.next

This topic is named in a candidate’s interview report: Technology off-campus interview, 2023, on GeeksforGeeks.

PythonEasy

What does this print?

def is_pal(s):
    i, j = 0, len(s) - 1
    while i < j:
        if s[i] != s[j]:
            return False
        i, j = i + 1, j - 1
    return True

print(is_pal("racecar"), is_pal("racecars"))

1. True True
2. False True
3. True False
4. False False

This topic is named in a candidate’s interview report: Technology off-campus interview, 2023, on GeeksforGeeks.

Operating systemsEasy

Which Linux command lists the files in the current directory sorted by last modification time, newest first?

1. ls -S
2. ls -t
3. sort -t
4. ls -r

This topic is named in a candidate’s interview report: Trainee software engineer interview, 2023 batch, on GeeksforGeeks.