[JAVA] 프로그래머스 - 기초문제 Day1 ~ Day3

https://school.programmers.co.kr/learn/challenges/training?order=acceptance_desc&languages=java

코딩 기초 트레이닝 | 프로그래머스 스쿨

 

Day 1

• 문자열 출력하기

import java.util.Scanner;

public class Solution {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String a = sc.next();
        System.out.print(a);
    }
}

 

• a와 b 출력하기

import java.util.Scanner;

public class Solution {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int a = sc.nextInt();
        int b = sc.nextInt();

        System.out.println("a = " + a);
         System.out.println("b = " + b);
    }
}

 

 

• 문자열 반복해서 출력하기

import java.util.Scanner;

public class Solution {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String str = sc.next();
        int n = sc.nextInt();
        
        System.out.print(str.repeat(n));
        
    }
}

 

 

• 대소문자 바꿔서 출력하기

import java.util.Scanner;

public class Solution {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String a = sc.next();
        
        for(char c : a.toCharArray()){
            if(Character.isUpperCase(c)){ 
                System.out.print(Character.toLowerCase(c));
            }else{
                System.out.print(Character.toUpperCase(c));
            }
        }
        
    }
}

 

 

• 특수문자 출력하기

import java.util.Scanner;

public class Solution {
    public static void main(String[] args) {
        System.out.print("!@#$%^&*(\\'\"<>?:;");
    }
}

 

---

Day 2

• 덧셈식 출력하기

import java.util.Scanner;

public class Solution {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int a = sc.nextInt();
        int b = sc.nextInt();

        System.out.println(a + " + " + b + " = " + (a + b));
    }
}

 

 

• 문자열 붙여서 출력하기

import java.util.Scanner;

public class Solution {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String a = sc.next();
        String b = sc.next();
        
        System.out.print(a+b);
    }
}

 

 

• 문자열 돌리기

import java.util.Scanner;

public class Solution {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String a = sc.next();
        
        for(char tmp : a.toCharArray()){
            System.out.println(tmp);
        }
    }
}

 

• 홀짝 구분하기

import java.util.Scanner;

public class Solution {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        
        System.out.print((n%2==0) ? n + " is even" : n+" is odd");
    }
}

 

 

• 문자열 겹쳐쓰기

class Solution {
    public String solution(String my_string, String overwrite_string, int s) {
        
        return my_string.substring(0,s) + overwrite_string + my_string.substring(overwrite_string.length() + s);
    }
}

 

 

---

Day 3

 

• 문자열 섞기

class Solution {
    public String solution(String str1, String str2) {
        String answer = "";
        
        for(int i=0;i<str1.length();i++){
            answer+=str1.toCharArray()[i];
            answer+=str2.toCharArray()[i];
        }
        return answer;
    }
}

 

 

• 문자 리스트를 문자열로 변환하기

class Solution {
    public String solution(String[] arr) {
        
        return String.join("",arr);
    }
}

 

 

• 문자열 곱하기

 

class Solution {
    public String solution(String my_string, int k) {
        
        return my_string.repeat(k);
    }
}

 

 

• 더 크게 합치기

class Solution {
    public int solution(int a, int b) {
        return Math.max(Integer.parseInt(String.valueOf(a) + String.valueOf(b)),Integer.parseInt(String.valueOf(b) + String.valueOf(a))) ;
    }
}

class Solution {
    public int solution(int a, int b) {
        int answer = 0;
        int aLong = Integer.parseInt(""+a+b);
        int bLong = Integer.parseInt(""+b+a);
        answer = aLong > bLong ? aLong : bLong;

        return answer;
    }
}

 

 

• 두 수의 연산값 비교하기

class Solution {
    public int solution(int a, int b) {
        return Math.max(Integer.parseInt(""+a+b),2*a*b);
    }
}