@@ -0,0 +1,42 @@
+package leetcodeEasyLevel;
+
+import java.util.Arrays;
+
+public class _0344ReverseString {
+
+  public static void reverseString(char[] s) {
+    //새로운 배열을 만들지않고 char array 역순으로 출력하는 문제
+
+    //sol1. Runtime 1 ms Memory 52.5 MB
+    /*
+    for (int i = 0; i < s.length / 2; i++) {
+      char temp = s[i];
+      s[i] = s[s.length - 1 - i]; //0 = 5, 1 = 4. 2 = 3
+      s[s.length - 1 - i] = temp;
+    }
+    */
+
+    //sol2 Runtime 1 ms Memory 53 MB
+    int st = 0, en = s.length - 1;
+    while (st < en) {
+      char temp = s[st];
+      s[st] = s[en];
+      s[en] = temp;
+      st++;
+      en--;
+    }
+
+    //print the result
+    System.out.println(Arrays.toString(s));
+  }
+
+  public static void main(String[] args) {
+    char[] ex1 = {'h', 'e', 'l', 'l', 'o' };
+    char[] ex2 = {'H', 'a', 'n', 'n', 'a', 'h' };
+
+    reverseString(ex1);
+    reverseString(ex2);
+    System.out.println("ex1 ans: [\"o\",\"l\",\"l\",\"e\",\"h\"]");
+    System.out.println("ex2 ans: [\"h\",\"a\",\"n\",\"n\",\"a\",\"H\"]");
+  }
+}