Fix typo

Author: nickolashkraus

src/flood_fill.py

@@ -6,7 +6,7 @@
 NOTES
   * Use breadth-first search.
 
-This problem is very straight-forward if you use breadth-first search. Simply
+This problem is very straightforward if you use breadth-first search. Simply
 add adjacent pixels that share the same color as the starting pixel to the
 queue and run the algorithm.
 

src/longest_repeating_character_replacement.py

@@ -13,7 +13,7 @@
   window size - frequency of most common character ≤ k
 
 Initially, I inverted the logic, searching instead for the longest substring
-with > k replacements. The correct solution is pretty straight-forward *if* you
+with > k replacements. The correct solution is pretty straightforward *if* you
 are working from the above premise. Additionally, I've added the canonical
 sliding window implementation. Its form should look familiar...
 """

src/string_compression.py

@@ -20,7 +20,7 @@
 be used to store the solution, the encoded string. Given that the array of the
 encoded string will contain at most 'n' elements, this is tractable.
 
-The solution is pretty straight-forward and can be solved in linear runtime
+The solution is pretty straightforward and can be solved in linear runtime
 complexity, O(n), and constant space complexity, O(1).
 
 We start with two pointers: