change java to md

Author: dev-jonghoonpark

best-time-to-buy-and-sell-stock/jonghoonpark.java renamed to best-time-to-buy-and-sell-stock/dev-jonghoonpark.md

@@ -1,11 +1,9 @@
-/*
- * https://leetcode.com/problems/best-time-to-buy-and-sell-stock/
- * time complexity : O(n)
- * space complexity : O(1)
- * https://jonghoonpark.com/2024/02/20/leetcode-121
- */
+- https://leetcode.com/problems/best-time-to-buy-and-sell-stock/
+- time complexity : O(n)
+- space complexity : O(1)
+- https://algorithm.jonghoonpark.com/2024/02/20/leetcode-121
 
-/*
+```java
 class Solution {
     public int maxProfit(int[] prices) {
         int buyAt = 0;
@@ -22,4 +20,4 @@ public int maxProfit(int[] prices) {
         return profit;
     }
 }
-*/
+```

contains-duplicate/dev-jonghoonpark.md

@@ -0,0 +1,22 @@
+- https://leetcode.com/problems/contains-duplicate/
+- time complexity : O(n)
+- space complexity : O(n)
+- https://algorithm.jonghoonpark.com/2024/04/24/leetcode-217
+
+```java
+import java.util.HashSet;
+import java.util.Set;
+
+class Solution {
+    public boolean containsDuplicate(int[] nums) {
+        Set<Integer> numSet = new HashSet<>();
+        for (int num : nums) {
+            if (numSet.contains(num)) {
+                return true;
+            }
+            numSet.add(num);
+        }
+        return false;
+    }
+}
+```

contains-duplicate/jonghoonpark.java

@@ -1,11 +1,9 @@
-/*
- * https://leetcode.com/problems/two-sum/
- * time complexity : O(n)
- * space complexity : O(n)
- * https://jonghoonpark.com/2024/01/03/leetcode-1
- */
+- https://leetcode.com/problems/two-sum/
+- time complexity : O(n)
+- space complexity : O(n)
+- https://algorithm.jonghoonpark.com/2024/01/03/leetcode-1
 
-/*
+```java
 import java.util.HashMap;
 import java.util.Map;
 
@@ -26,4 +24,4 @@ public int[] twoSum(int[] nums, int target) {
         return null;
     }
 }
-*/
+```

two-sum/jonghoonpark.java renamed to two-sum/dev-jonghoonpark.md

@@ -0,0 +1,18 @@
+- https://leetcode.com/problems/valid-anagram/
+- time complexity : O(nlogn)
+- space complexity : O(n)
+- https://algorithm.jonghoonpark.com/2024/04/24/leetcode-242
+
+```java
+import java.util.Arrays;
+
+class Solution {
+    public boolean isAnagram(String s, String t) {
+        char[] temp1 = s.toCharArray();
+        char[] temp2 = t.toCharArray();
+        Arrays.sort(temp1);
+        Arrays.sort(temp2);
+        return Arrays.equals(temp1, temp2);
+    }
+}
+```

valid-anagram/dev-jonghoonpark.md

@@ -1,19 +1,9 @@
-/*
- * https://leetcode.com/problems/valid-palindrome/
- * time complexity : O(n)
- * space complexity : O(n)
- * https://jonghoonpark.com/2024/04/24/leetcode-125
- */
-
-/*
-
-void main() {
-    Solution solution = new Solution();
-    System.out.println(solution.isPalindrome("A man, a plan, a canal: Panama")); // true
-    System.out.println(solution.isPalindrome("race a car")); // false
-    System.out.println(solution.isPalindrome(" ")); // true
-}
+- https://leetcode.com/problems/valid-palindrome/
+- time complexity : O(n)
+- space complexity : O(n)
+- https://algorithm.jonghoonpark.com/2024/04/24/leetcode-125
 
+```java
 class Solution {
     public boolean isPalindrome(String s) {
         StringBuilder filtered = new StringBuilder();
@@ -35,5 +25,4 @@ public boolean isPalindrome(String s) {
         return true;
     }
 }
-
-*/
+```