#3: description update

Author: vetalapo

c-sharp/Problems/sliding-window/LongestSubstringWithoutRepeatingCharacters.cs

@@ -19,12 +19,13 @@
  * Example 3:
  *   Input: s = "pwwkew"
  *   Output: 3
- *   Explanation: 
+ *   Explanation:
  *     The answer is "wke", with the length of 3.
- *     Notice that the answer must be a substring, "pwke" is a subsequence and not a substring.
+ *     Notice that the answer must be a substring,
+ *     "pwke" is a subsequence and not a substring.
  *
  * Constraints:
- *   • 0 <= s.length <= 5 * 104
+ *   • 0 <= s.length <= 5 * 10^4
  *   • s consists of English letters, digits, symbols and spaces.
  **
  * https://leetcode.com/problems/longest-substring-without-repeating-characters/