Fix bug in hint and add explanations

08/kth-missing-positive-number.checkpoint.md

@@ -108,7 +108,8 @@ Implement `kth_missing_positive_number`.  Use these tests to guide your solution
 ```python
 def kth_missing_positive_number(numbers, k):
     '''
-    INPUT: List of positive numbers in increating order & a positive integer k
+    INPUT: List of positive integers in increasing order & a positive integer k
+
     OUTPUT: The kth missing number
     '''
 

08/kth-missing-positive-number.md

@@ -206,15 +206,20 @@ Write the logical steps here.
 Example Steps for an O(n) solution:
 
 1. Check for valid input
-1. if `k < arr[0]`
+1. if `k < arr[0]:`
     * `return k`
 1. Set `index` to `0`
-1. `while index < len(arr) - 1`
+2. `k = k - arr[0] - 1` 
+    * `k` will be decremented to represent the number of remaining missing nums. This line accounts for missing nums before `arr[0]`.
+4. `while index < len(arr) - 1:`
     * `current_missing = arr[index + 1] - arr[index] - 1`
-    * `if k <= current_missing`
+        *  `current_missing` represents how many missing numbers between `arr[index + 1]` and `arr[index]`
+    * `if k <= current_missing:`  
+        *  We found the original kth missing number. The value is `arr[index] + k`. We return it and exit the loop.
         * `return arr[index] + k`
     * `k = k - current_missing`
-1. return the last element of the list plus the remaining value of `k`.
+    * `index = index + 1`
+5. return the last element of the list plus the remaining value of `k`.
 
 ### !end-explanation