Day 07 - 코딩테스트 입문(Java)

1. 특정 문자 제거하기

https://school.programmers.co.kr/learn/courses/30/lessons/120826

프로그래머스

class Solution {
    public String solution(String my_string, String letter) {
        String answer = "";
        
        answer = my_string.replace(letter, "");
        
        return answer;
    }
}

 

2. 각도기

https://school.programmers.co.kr/learn/courses/30/lessons/120829

프로그래머스

▼ 방법 1

class Solution {
    public int solution(int angle) {
        int answer = 0;
        
        if(0 < angle && angle < 90) {
            answer = 1;
        } else if(angle == 90) {
            answer = 2;
        } else if(90 < angle && angle < 180) {
            answer = 3;
        } else if(angle == 180) {
            answer = 4;
        }
        
        return answer;
    }
}

 

▼ 방법 2

class Solution {
    public int solution(int angle) {
        int answer = 0;
        
        answer = angle == 180 ? 4 : angle < 90 ? 1 : angle == 90 ? 2 : 3;
        
        return answer;
    }
}

 

3. 양꼬치

https://school.programmers.co.kr/learn/courses/30/lessons/120830

프로그래머스

▼ 방법 1

class Solution {
    public int solution(int n, int k) {
        int answer = 0;
        
        answer = (12000 * n) + (2000 * k) - (2000 * (n / 10));
        
        return answer;
    }
}

 

▼ 방법 2

class Solution {
    public int solution(int n, int k) {
        int answer = 0;
        
        answer = (12000 * n) + (2000 * (k - n / 10));
        
        return answer;
    }
}

 

4. 짝수의 합

https://school.programmers.co.kr/learn/courses/30/lessons/120831

프로그래머스

▼ 방법 1

class Solution {
    public int solution(int n) {
        int answer = 0;
        
        for(int i = 1; i <= n; i++) {
            answer += i % 2 == 0 ? i : 0;
        }
        
        return answer;
    }
}

 

▼ 방법 2

class Solution {
    public int solution(int n) {
        int answer = 0;
        
        for(int i = 2; i <= n; i += 2) {
            answer += i;
        }
        
        return answer;
    }
}

 

▼ 방법 3

import java.util.stream.IntStream;

class Solution {
    public int solution(int n) {
        int answer = 0;
        
        answer = IntStream.rangeClosed(1, n).filter(i -> i % 2 == 0).sum();
        
        return answer;
    }
}