Merge pull request #2464 from Hyeri1ee/main

[Hyeri1ee] WEEK 03 Solutions

Author: SamTheKorean

number-of-1-bits/Hyeri1ee.java

@@ -0,0 +1,20 @@
+import java.util.*;
+
+
+class Solution {
+    public int hammingWeight(int n) {
+
+        int answer =0;
+        while (n > 0){
+            if ((n & 1) == 1){
+                answer++;
+                
+            }
+            n >>>= 1;//unsigned shift
+            
+        }
+
+        return answer;
+        
+    }
+}

valid-palindrome/Hyeri1ee.java

@@ -0,0 +1,48 @@
+import java.util.*;
+
+//palindrome
+class Solution {
+    public boolean isPalindrome(String s) {
+
+        ArrayList<Character> list = new ArrayList<>();
+        //list에 넣기
+        for (int i = 0; i < s.length(); i++) {
+            char c = s.charAt(i);
+
+            if (!Character.isLetterOrDigit(c))
+                continue;
+
+            list.add(c);
+        }
+
+        System.out.println(list.size());
+
+        boolean ok = true;
+        int start = 0;
+        int end = list.size() - 1;
+
+        if (list.size() == 0 || list.size() == 1)
+            return true;
+
+        //디버깅
+        for (int i = 0; i < list.size(); i++) {
+            System.out.println(list.get(i));
+        }
+
+        while (start < end) {
+            if (Character.toLowerCase(list.get(start)) != 
+    Character.toLowerCase(list.get(end))) {
+    return false;
+}
+
+            start++;end--;
+        } //end of while
+
+        return ok;
+    }
+
+    private static boolean isInRange(char c) {
+        return (c >= 'A') && (c <= 'Z') || (c >= 'a') && (c <= 'z');
+    }
+
+}