toCharArray toLowerCase Character.isUpperCase / Str.toCharArray
StringTokenizer String.split indexOf / String.valueOf StringBuilder.reverse
Character.isAlphabetic('') / String.contains charSequence
Str.equalsIgnoreCase / Str.replaceAll
Character.isDigit / Math.min
10진법 변환Integer.parseInt(str, 2) 2진법 변환 Integer.toBinaryString(int)
TwoPoiners / Arrays.sort / Arrays.sort(Collections.reversOrder())
sliding window
Sliding Window / two pointers
hashMap.containsKey
Two pointers / HashMap / Sliding Windows / hsMap.equals
TreeSet(Collections.reverseOrder()); / ts.size() / ts.remove() / Stack
Stack.get() / Stack.peek()
Stack
Queue / Q.contains() / Q.peek() / Q.poll() / Q.offer()
Class변수 / 중복확인
Bubble Sort / Insertion Sort
LRU / 선택정렬(Selection Sort)
List<ClassType>의 정렬 / Comparator / Comparable
Binary Search / Array.stream(arr).max().getAsInt(); / Array.stream(arr).sum();
DFS 문제모음