solves #2299: Strong Password Checker II in java

Author: anishLearnsToCode

Diff for: README.md

@@ -740,7 +740,7 @@
 | 2283 | [Check if Number Has Equal Digit Count and Digit Value](https://leetcode.com/problems/check-if-number-has-equal-digit-count-and-digit-value)                           |                                                                        [![Java](assets/java.png)](src/CheckIfNumberHasEqualDigitCountAndDigitValue.java)                                                                         |                                                                                                                                   |
 | 2287 | [Rearrange Characters to Make Target String](https://leetcode.com/problems/rearrange-characters-to-make-target-string)                                                 |                                                                            [![Java](assets/java.png)](src/RearrangeCharactersToMakeTargetString.java)                                                                            |                                                                                                                                   |
 | 2293 | [Min Max Game](https://leetcode.com/problems/min-max-game)                                                                                                             |                                                                                         [![Java](assets/java.png)](src/MinMaxGame.java)                                                                                          |                                                                                                                                   |
-| 2299 | [Strong Password Checker II](https://leetcode.com/problems/strong-password-checker-ii)                                                                                 |                                                                                                                                                                                                                                  |                                                                                                                                   |
+| 2299 | [Strong Password Checker II](https://leetcode.com/problems/strong-password-checker-ii)                                                                                 |                                                                                   [![Java](assets/java.png)](src/StrongPasswordCheckerII.java)                                                                                   |                                                                                                                                   |
 | 2300 | [Successful Pairs of Spells and Potions](https://leetcode.com/problems/successful-pairs-of-spells-and-potions)                                                         |                                                                        [![Python](assets/python.png)](python/successfull_pairs_of_spells_and_potions.py)                                                                         |                                                                                                                                   |
 | 2303 | [Calculate Amount Paid in Taxes](https://leetcode.com/problems/calculate-amount-paid-in-taxes)                                                                         |                                                                        [![Python](assets/python.png)](python/successfull_pairs_of_spells_and_potions.py)                                                                         |                                                                                                                                   |
 | 2315 | [Count Asterisks](https://leetcode.com/problems/count-asterisks)                                                                                                       |                                                                        [![Python](assets/python.png)](python/successfull_pairs_of_spells_and_potions.py)                                                                         |                                                                                                                                   |

Diff for: src/StrongPasswordCheckerII.java

@@ -0,0 +1,77 @@
+// https://leetcode.com/problems/strong-password-checker-ii
+// T: O(|password|)
+// S: O(1)
+
+import java.util.HashSet;
+import java.util.Set;
+
+public class StrongPasswordCheckerII {
+    private static final String SPECIAL_CHARACTERS = "!@#$%^&*()-+";
+
+    public boolean strongPasswordCheckerII(String password) {
+        return atLeastLen8(password)
+                && atLeast1LowercaseLetter(password)
+                && atLeast1UppercaseLetter(password)
+                && atLeast1Digit(password)
+                && atLeast1SpecialCharacter(password)
+                && noAdjacentSameCharacters(password);
+    }
+
+    private boolean noAdjacentSameCharacters(String password) {
+        for (int i = 1 ; i < password.length() ; i++) {
+            if (password.charAt(i - 1) == password.charAt(i)) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    private boolean atLeast1SpecialCharacter(String password) {
+        final Set<Character> characters = charactersOf(password);
+        for (int i = 0 ; i < SPECIAL_CHARACTERS.length() ; i++) {
+            if (characters.contains(SPECIAL_CHARACTERS.charAt(i))) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private Set<Character> charactersOf(String password) {
+        final Set<Character> set = new HashSet<>();
+        for (int i = 0 ; i < password.length() ; i++) {
+            set.add(password.charAt(i));
+        }
+        return set;
+    }
+
+    private boolean atLeast1Digit(String password) {
+        for (int i = 0 ; i < password.length() ; i++) {
+            if (password.charAt(i) >= '0' && password.charAt(i) <= '9') {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private boolean atLeast1UppercaseLetter(String password) {
+        for (int i = 0 ; i < password.length() ; i++) {
+            if (password.charAt(i) >= 'A' && password.charAt(i) <= 'Z') {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private boolean atLeast1LowercaseLetter(String password) {
+        for (int i = 0 ; i < password.length() ; i++) {
+            if (password.charAt(i) >= 'a' && password.charAt(i) <= 'z') {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private boolean atLeastLen8(String password) {
+        return password.length() >= 8;
+    }
+}