코딩테스트 입문 - Day 14

가까운 수

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import java.util.*;

class Solution {
    public int solution(int[] array, int n) {
        int min = 101;
        for(int i = 0; i< array.length;i++){
            if(Math.abs(min - n) > Math.abs(array[i] - n)){
                min = array[i];
            }else if(Math.abs(min - n) == Math.abs(array[i] - n)){
                min = Math.min(min, array[i]);
            }
        }
        return min;
    }
}

369 게임

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class Solution {
    public int solution(int order) {
        String orderStr = order + "";
        return orderStr.length() - orderStr.replaceAll("[369]","").length();
    }
}

암호 해독

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class Solution {
    public String solution(String cipher, int code) {
        StringBuilder sb = new StringBuilder();
        for(int i =code; i<=cipher.length(); i+=code){
            sb.append(cipher.charAt(i-1));
        }
        return sb.toString();
    }
}

대문자와 소문자

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class Solution {
    public String solution(String my_string) {
        StringBuilder sb = new StringBuilder();
        for(int i =0;i<my_string.length();i++){
            int c = my_string.charAt(i);
            if(c >= 65 && c <=91){
                sb.append((char)(c + 32));
            }else{
                sb.append((char)(c - 32));
            }
        }
        return sb.toString();
    }
}