주어진 문자열에서, 중복된 문자는 제거하는 코드를 작성하라 apple -> aple banana -> ban 풀이 indexOf 활용 HashSet 활용 stream의 distinct 활용 성능 1. 풀이 1.1. indexOf 활용 문자열 s의 각 문자를 순회하며 StringBuilder sb에 아직 입력되지 않은 문자를 추가한다. 문자가 sb에 포함되어있지 않다면 추가 포함되어있다면 추가하지 않으면 된다. static String removeDuplicates1(String s) { if (s == null || s.isBlank()) { return s; } StringBuilder sb = new StringBuilder(); for (char c : s.toCharArray()) { if (sb..

MinAvgTwoSlice A non-empty array A consisting of N integers is given. A pair of integers (P, Q), such that 0 ≤ P < Q < N, is called a slice of array A (notice that the slice contains at least two elements). The average of a slice (P, Q) is the sum of A[P] + A[P + 1] + ... + A[Q] divided by the length of the slice. To be precise, the average equals (A[P] + A[P + 1] + ... + A[Q]) / (Q − P + 1). Fo..

FrogRiverOne Find the earliest time when a frog can jump to the other side of a river. A small frog wants to get to the other side of a river. The frog is initially located on one bank of the river (position 0) and wants to get to the opposite bank (position X+1). Leaves fall from a tree onto the surface of the river. You are given an array A consisting of N integers representing the falling lea..

PermMissingElem Find the missing element in a given permutation. An array A consisting of N different integers is given. The array contains integers in the range [1..(N + 1)], which means that exactly one element is missing. Your goal is to find that missing element. Write a function: class Solution { public int solution(int[] A); } that, given an array A, returns the value of the missing elemen..

FrogJmp Count minimal number of jumps from position X to Y. A small frog wants to get to the other side of the road. The frog is currently located at position X and wants to get to a position greater than or equal to Y. The small frog always jumps a fixed distance, D. Count the minimal number of jumps that the small frog must perform to reach its target. Write a function: class Solution { public..

OddOccurrencesInArray Find value that occurs in odd number of elements. A non-empty array A consisting of N integers is given. The array contains an odd number of elements, and each element of the array can be paired with another element that has the same value, except for one element that is left unpaired. For example, in array A such that: A[0] = 9 A[1] = 3 A[2] = 9 A[3] = 3 A[4] = 9 A[5] = 7 ..