Goldman Sachs interview prep

DSAEasy

Which data structure is the natural fit for checking whether brackets like ([]{}) are balanced?

1. A stack
2. A queue
3. A hash set
4. A binary search tree

This topic is named in a candidate’s interview report: Summer internship interview, 2020, on GeeksforGeeks.

DSAMedium

You merge n sorted arrays of k elements each into one sorted array, using a min-heap that holds the smallest unused element of each array. What is the time complexity?

1. O(nk log n)
2. O(nk log nk)
3. O(nk)
4. O(n^2 k)

This topic is named in a candidate’s interview report: Summer internship interview, 2020, on GeeksforGeeks.

DSAMedium

How can you reverse a queue without a second queue or an explicit stack?

1. Dequeue each element and enqueue it again once
2. Recursively: dequeue the front, reverse the rest, then enqueue the saved element at the back
3. Sort the queue in descending order
4. It cannot be done

This topic is named in a candidate’s interview report: On-campus internship interview, on GeeksforGeeks.

DSAEasy

An undirected graph has 7 edges. What is the sum of the degrees of all its vertices?

1. 7
2. 49
3. It depends on the number of vertices
4. 14

This topic is named in a candidate’s interview report: On-campus internship interview, on GeeksforGeeks.

PythonMedium

Which statement about C++ and Python (the standard CPython) is true?

1. Python checks types at compile time and C++ only at run time
2. C++ is compiled to machine code before it runs; CPython compiles to bytecode and interprets it, so plain Python loops are usually much slower
3. C++ frees memory automatically with a garbage collector and Python does not
4. Both run on the Java virtual machine

This topic is named in a candidate’s interview report: Summer internship interview, 2020, on GeeksforGeeks.

DBMS and SQLMedium

emp has 4 rows in dept "eng", 2 in "ops" and 3 in "hr". Which departments does this return?

SELECT dept FROM emp
GROUP BY dept
HAVING COUNT(*) > 2
ORDER BY dept;

1. eng, hr and ops
2. eng only
3. eng and hr
4. hr and ops

This topic is named in a candidate’s interview report: Summer internship interview, 2020, on GeeksforGeeks.

Software engineeringMedium

What is a branch in git, technically?

1. A full copy of every file in the repository
2. A separate repository on the server
3. A movable pointer to a commit, which moves forward as you commit on it
4. A backup git makes before each commit

This topic is named in a candidate’s interview report: On-campus internship interview, on GeeksforGeeks.

AptitudeMedium

Two ropes each take exactly 60 minutes to burn, but they burn unevenly, so half a rope does not take 30 minutes. How do you measure exactly 45 minutes?

1. Light rope A at both ends and rope B at one end; when A burns out, light the other end of B, which burns out 15 minutes later
2. Cut each rope in half and burn the pieces one after another
3. Light both ropes at one end and stop when three quarters of A has burned
4. Light rope A at both ends, then rope B at both ends

This topic is named in a candidate’s interview report: On-campus internship interview, on GeeksforGeeks.