[sumin] 2주차 문제 풀이

week1/sumin/Backjoon_1000.java

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+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.StringTokenizer;
+
+public class Backjoon_1000 {
+    public static void main(String[] args) throws IOException {
+
+		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+
+ 		String str = br.readLine();
+		StringTokenizer st = new StringTokenizer(str," ");
+		int a = Integer.parseInt(st.nextToken());
+		int b = Integer.parseInt(st.nextToken());
+
+		System.out.println(a+b);
+    }
+
+}

week1/sumin/Backjoon_1001.java

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+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.StringTokenizer;
+
+class BackJoon_1001{
+    public static void main(String[]args) throws IOException{
+        BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
+        String str=br.readLine();
+        StringTokenizer st=new StringTokenizer(str," ");
+        int A=Integer.parseInt(st.nextToken());
+        int B=Integer.parseInt(st.nextToken());
+
+        System.out.println(A-B);
+    }
+}

week1/sumin/Backjoon_1008.java

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+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.StringTokenizer;
+
+public class Backjoon_1008 {
+    public static void main(String[]args)throws IOException{
+        BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
+        String str=br.readLine();
+        StringTokenizer st=new StringTokenizer(str," ");
+        int A=(int) Double.parseDouble(st.nextToken());
+        int B=(int) Double.parseDouble(st.nextToken());
+
+        System.out.println(A/B);
+    }
+}

week1/sumin/Backjoon_10171.java

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+import java.io.BufferedWriter;
+import java.io.IOException;
+import java.io.OutputStreamWriter;
+
+public class Backjoon_10171{
+    public static void main(String[] args) throws IOException {
+		BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+
+		bw.write("\\    /\\");
+		bw.newLine();	// 줄 구분자
+
+		bw.write(" )  ( ')");
+		bw.newLine();	
+
+		bw.write("(  /  )");
+		bw.newLine();
+
+		bw.write(" \\(__)|");
+
+		bw.flush();
+		bw.close();
+	}
+}

week1/sumin/Backjoon_10172.java

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+import java.io.BufferedWriter;
+import java.io.IOException;
+import java.io.OutputStreamWriter;
+
+public class Backjoon_10172 {
+    public static void main(String[] args)throws IOException{
+
+		BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+
+		bw.write("|\\_/|\n");  
+		bw.write("|q p|   /}\n");     
+		bw.write("( 0 )\"\"\"\\\n");   
+		bw.write("|\"^\"`    |\n");   
+		bw.write("||_/=\\\\__|\n");    
+
+		bw.flush();
+        bw.close();
+	}
+
+}

week1/sumin/Backjoon_10430.java

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+import java.io.BufferedReader;
+import java.io.BufferedWriter;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.OutputStreamWriter;
+import java.util.StringTokenizer;
+
+class Backjoon_10430{
+    public static void main(String[]args)throws IOException{
+        BufferedReader bf=new BufferedReader(new InputStreamReader(System.in));
+        BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(System.out));
+        StringTokenizer st=new StringTokenizer(bf.readLine()," ");
+
+        int a=Integer.parseInt(st.nextToken());
+        int b=Integer.parseInt(st.nextToken());
+        int c=Integer.parseInt(st.nextToken());
+
+        bw.write((a+b)%c+"\n");
+        bw.write(((a%c)+(b%c))%c+"\n");
+        bw.write((a*b)%c+"\n");
+        bw.write(((a%c)*(b%c))%c+"\n");
+
+        bw.flush();
+        bw.close();
+    }
+}

week1/sumin/Backjoon_10869.java

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+import java.io.BufferedReader;
+import java.io.BufferedWriter;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.OutputStreamWriter;
+import java.util.StringTokenizer;
+
+public class Backjoon_10869 {
+    public static void main(String[] args) throws IOException {
+        BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
+        BufferedWriter bw= new BufferedWriter(new OutputStreamWriter(System.out));
+        String input=br.readLine();
+
+        StringTokenizer st= new StringTokenizer(input," ");
+        int a= Integer.parseInt(st.nextToken());
+        int b=Integer.parseInt(st.nextToken());
+
+        bw.write(Integer.toString(a-b));
+        bw.write(Integer.toString(a-b));
+        bw.write(Integer.toString(a*b));
+        bw.write(Integer.toString(a/b));
+        bw.write(Integer.toString(a%b));
+
+        bw.flush();
+        bw.close();
+    }
+
+}

week1/sumin/Backjoon_10926.java

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+import java.io.BufferedReader;
+import java.io.BufferedWriter;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.OutputStreamWriter;
+
+public class Backjoon_10926 {
+    public static void main(String[] args) throws IOException{
+        BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
+        BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(System.out));
+        String year=br.readLine();
+
+        bw.write(year);
+        bw.write("??!");
+
+        bw.flush();
+        bw.close();
+
+    }
+
+}

week1/sumin/Backjoon_2557.java

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+import java.io.BufferedWriter;
+import java.io.IOException;
+import java.io.OutputStreamWriter;
+
+public class Backjoon_2557 {
+    public static void main(String[] args) throws IOException{
+        BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(System.out));
+        bw.write("Hello World!");
+
+        bw.flush();
+        bw.close();
+    }
+}

week1/sumin/Backjoon_3033.java

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+import java.io.BufferedReader;
+import java.io.BufferedWriter;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.OutputStreamWriter;
+import java.util.StringTokenizer;
+
+class BackJoon_3033{
+    public static void main(String[] args) throws IOException{
+        BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
+        String input=br.readLine();
+        StringTokenizer st=new StringTokenizer(input," ");
+        BufferedWriter bw= new BufferedWriter(new OutputStreamWriter(System.out));
+        int king = Integer.parseInt(st.nextToken());
+        int queen=Integer.parseInt(st.nextToken());
+        int rook=Integer.parseInt(st.nextToken());
+        int bishop=Integer.parseInt(st.nextToken());
+        int knight=Integer.parseInt(st.nextToken());
+        int pawn=Integer.parseInt(st.nextToken());
+
+        bw.write(Integer.toString(1-king)+" ");
+        bw.write(Integer.toString(1-queen)+" ");
+        bw.write(Integer.toString(2-rook)+" ");
+        bw.write(Integer.toString(2-bishop)+" ");
+        bw.write(Integer.toString(2-knight)+" ");
+        bw.write(Integer.toString(8-pawn)+" ");
+
+        bw.flush();
+        bw.close();
+    }
+}

week1/sumin/Stream(스트림).md

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+# 스트림(Stream)
+
+### 스트림이란?
+---
+
+스트림은 데이터의 이동 흐름이다.
+
+즉, A수도관에서 B수도관으로 이동하는 물의 흐름이라고 할 수 있다.
+
+프로그래밍에서는 다음과 같은 것들을 스트림이라고 한다.
+
+- HTTP 응답 데이터(브라우저가 요청하고 서버가 응답하는 HTTP 응답 데이터)
+
+<img width="675" alt="스크린샷 2023-01-07 오후 12 39 02" src="https://user-images.githubusercontent.com/88534959/211129615-8e934752-3f4b-4ce9-aa68-e91fb3f5aef0.png">
+
+
+용도에 따라 입력 스트림(InputStream), 출력 스트림(OutputStream)으로 나뉜다.
+
+```java
+BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
+```
+
+### InpuStream
+---
+
+바이트 단위로 데이터를 처리한다.
+
+```java
+import java.io.IOException;
+import java.io.InputStream;
+
+public class StreamTest {
+    public static void main(String[] args) throws IOException {
+        InputStream in=System.in;
+
+        int a;
+        a=in.read();
+
+        System.out.println(a);
+
+    }
+}
+```
+
+read()메서드는 1Byte의 int 자료형으로 값을 받는다.
+
+이 int값은 아스키코드 값이기 때문에 숫자를 입력해도 아스키 코드 값으로 출력된다.
+
+```java
+1 //입력값
+49 //출력값
+```
+
+또한, System.in의 타입도 InputStream이다.
+<img width="592" alt="스크린샷 2023-01-07 오후 12 12 47" src="https://user-images.githubusercontent.com/88534959/211129556-ae1140a7-d33e-46f9-9b41-e2c954342cab.png">
+
+이 방법만으로는 문자를 받기 힘드니 InputStreamReader를 사용해서 바이트 단위 데이터를 문자 단위로 처리할 수 있게하였다.
+
+### InputStreamReader
+---
+
+문자(Character) 단위로 데이터를 처리한다.
+
+InputStream의 데이터를 문자로 변환하는 중개 역할을 한다.
+
+```java
+InputStreamReader reader = new InputStreamReader(new InputStream);
+```
+
+InputStreamReader은 InputStream 객체를 입력으로 가지고 있어야 한다.
+<img width="515" alt="스크린샷 2023-01-07 오후 12 17 28" src="https://user-images.githubusercontent.com/88534959/211129568-27195f96-1456-4922-a4f2-87cea652e819.png">
+
+### BufferedReader
+---
+버퍼를 두어 문자를 버퍼에 일정 정도 저장해둔 뒤 한 번에 보낸다.
+
+```java
+BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
+```
+
+```java
+InputStream inputstream = System.in;
+InputStreamReader sr = new InputStreamReader(inputstream);
+BufferedReader br = new BufferedReader(sr);
+```
+
+1. **바이트 단위**로 데이터를 처리하는 InputStream를 통해서 데이터를 입력받는다.,
+2. 바이트 단위 데이터를 **문자(Character) 단위**로 처리하기 위해서 InputStreamReader로 감싸준다.
+3. 버퍼(Buffer)를 이용해 입력받은 문자를 쌓아둔 뒤 한 번에 **문자열(String)**로 보낸다.
+
+[System.in](http://System.in) == InputStream → InputStreamReader → BufferedReader
+
+바이트 단위 → Char 단위 → String 단위