## Win After Last Round - Microsoft Top Interview Questions

You are given a list of integers nums of length n representing the current score of swimmers in a competition. There is one more round to swim and the first place winner for this round gets n points, second place n-1 points, etc. and the last place gets 1 point. Return the number of swimmers that can still win the competition after the last round. If you tie for first in points, this still counts as winning. Constraints n ≤ 100,000 where n is the length of nums Example 1 Input

## Word Machine - Microsoft Top Interview Questions

You are given a list of strings ops where each element is either: A non-negative integer that should be pushed into a stack "POP" meaning pop the top element in the stack "DUP" meaning duplicate the top element in the stack "+" meaning pop the top two and push the sum "-" meaning pop the top two and push top - second Return the top element in the stack after applying all operations. If there are any invalid operations, return -1. Constraints 1 ≤ n ≤ 100,000 wher

## Even Frequency - Facebook Top Interview Questions

Given a list of integers nums, return whether all numbers appear an even number of times. This should be done in \mathcal{O}(1)O(1) space. Constraints n ≤ 100,000 where n is the length of nums Example 1 Input nums = [2, 4, 4, 2, 3, 3] Output True Explanation Every number occurs twice. Example 2 Input nums = [1] Output False Explanation 1 occurs an odd number of times.