Microsoft OA | SDE 2 | Redmond

Round 1

Questions:

1. Given a string of letters, containing both uppercase and lowercase letters, return the number of different characters where all lowercase of that character appear before any uppercase letter.
   Example:
   Input: aaAbcCABBc
   Output: 2 (a and b are counted, c is not counted)

2. Given 2 balls Red and White, return the minimum number of swaps required where we want to arrange all the red balls into a consistent segment (in one move, you can swap adjacent ones).
   Example:
   Input: WRRWRW
   Output: 2 (resulting arrangement: WRRRWW)

3. Given a String S representing positive digits containing n numbers, and given k (number of moves), you can replace any number other than 5, return the maximum number possible within k moves.
   Example:
   Input: 165232, k=3
   Output: 565552