• Input: [2, 14, 5, 53, 26, 33, 53, 33, 12]
  • Output: 33 (second largest), 26 (third largest)

  • Assumption: Input contains at least two or three numbers.

  • Interviewer: Find second largest number.

 

 

  • Quick code using list sorted() and set()
numbers = [2, 14, 5, 53, 26, 33, 53, 33, 12]
sorted_unique_numbers = sorted(set(numbers))
second_largest = sorted_unique_numbers[-2]
print(second_largest)

 

 

  • Interviewer: Rewrite without sorted() and set().
numbers = [2, 14, 5, 53, 26, 33, 53, 33, 12]
largest = second_largest = -math.inf
for num in numbers:
    if num == largest:
        continue
    if num > largest:
        second_largest = largest
        largest = num
    elif num > second_largest:
        second_largest = num
print(second_largest)

 

 

  • Interviewer: Rewrite the code to find the third largest.
numbers = [2, 14, 5, 53, 26, 33, 53, 33, 12]
largest = second_largest = third_largest = -math.inf
for num in numbers:
    if num == largest:
        pass
    elif num > largest:
        third_largest = second_largest
        second_largest = largest
        largest = num
    elif num == second_largest:
        pass
    elif num > second_largest:
        third_largest = second_largest
        second_largest = num
    elif num > third_largest:
        third_largest = num

print(third_largest)
  • Interviewer: Why did you use pass instead of continue ?
  • Me: pass
  • Interviewer: What? My question is: why did you use pass?
  • Me: I said pass, which means move to the next question!
  • Interviewer: 🤓