docs: add approach + note on constraints

algorithms/arrays/0014-longest-common-prefix/README.md

@@ -6,24 +6,42 @@ Write a function to find the longest common prefix string amongst an array of st
 
 If there is no common prefix, return an empty string "".
 
-### Example 1:
+- ### Example 1:
 
-Input: `strs = ["flower","flow","flight"]`
+  Input: `strs = ["flower","flow","flight"]`
 
-Output: `"fl"`
+  Output: `"fl"`
 
-### Example 2:
+- ### Example 2:
 
-Input: `strs = ["dog","racecar","car"]`
+  Input: `strs = ["dog","racecar","car"]`
 
-Output: `""`
+  Output: `""`
 
-Explanation: There is no common prefix among the input strings.
+  Explanation: There is no common prefix among the input strings.
 
-### Constraints:
+## Constraints:
 
 `1 <= strs.length <= 200`
 
 `0 <= strs[i].length <= 200`
 
 `strs[i]` consists of only lowercase English letters if it is non-empty.
+
+## Approach:
+
+At the moment, I’m not explicitly enforcing the problem constraints in the code.
+The input is assumed to satisfy the given bounds:
+the number of strings is limited, each string has bounded length, and characters are lowercase English letters.
+
+Since these constraints do not affect the algorithmic strategy or complexity, I treat them as preconditions.
+If needed, they can be added later as explicit validation or assertions without changing the core logic.
+
+## Note on constraints
+
+At the moment, I’m not explicitly enforcing the problem constraints in the code.
+The input is assumed to satisfy the given bounds:
+the number of strings is limited, each string has bounded length, and characters are lowercase English letters.
+
+Since these constraints do not affect the algorithmic strategy or complexity, I treat them as preconditions.
+If needed, they can be added later as explicit validation or assertions without changing the core logic.