PR : 2주차 문제 풀이

src/main/java/sgyj/inflearn/ReadMe.md

@@ -20,3 +20,18 @@
 
 ***
 
+***
+## 2주차.
+- 2-1
+  - [11. 문자열 압축](https://cote.inflearn.com/contest/10/problem/01-11)
+  - [12. 암호](https://cote.inflearn.com/contest/10/problem/01-12)
+  - [1. 큰 수 출력하기](https://cote.inflearn.com/contest/10/problem/02-01)
+  - [2. 보이는 학생](https://cote.inflearn.com/contest/10/problem/02-02)
+  - [3. 가위 바위 보](https://cote.inflearn.com/contest/10/problem/02-03)
+- 2-2
+  - [4. 피보나치 수열](https://cote.inflearn.com/contest/10/problem/02-04)
+  - [5. 소수(에라토스테네스 체)](https://cote.inflearn.com/contest/10/problem/02-05)
+  - [6. 뒤집은 소수](https://cote.inflearn.com/contest/10/problem/02-06)
+  - [7. 점수계산](https://cote.inflearn.com/contest/10/problem/02-07)
+  - [8. 등수구하기](https://cote.inflearn.com/contest/10/problem/02-08)
+***

src/main/java/sgyj/inflearn/study/week2/Solution11.java

@@ -0,0 +1,28 @@
+package sgyj.inflearn.study.week2;
+
+import java.util.Scanner;
+
+public class Solution11 {
+
+    public String solution(String s){
+        String answer="";
+        s = s+ " ";
+        int cnt = 1;
+        for(int i=0; i<s.length()-1; i++){
+            if(s.charAt( i ) == s.charAt( i+1 )) cnt++;
+            else{
+                answer += s.charAt( i );
+                if(cnt > 1) answer+= String.valueOf( cnt );
+                cnt = 1;
+            }
+        }
+        return answer;
+    }
+
+    public static void main(String[] args){
+        Scanner in=new Scanner( System.in);
+        sgyj.inflearn.yeji.week2.Solution11 solution11 = new sgyj.inflearn.yeji.week2.Solution11();
+        System.out.println( solution11.solution( in.nextLine() ) );
+
+    }
+}

src/main/java/sgyj/inflearn/study/week2/Solution12.java

@@ -0,0 +1,28 @@
+package sgyj.inflearn.study.week2;
+
+import java.util.Scanner;
+
+public class Solution12 {
+    /*
+    * Integer.parseInt();
+    * */
+    public static String solution(int n , String s){
+        String answer = "";
+        for(int i=0; i<n; i++){
+            String tmp = s.substring( 0,7 ).replace( '#','1' ).replace( '*','0' );
+            int num = Integer.parseInt( tmp,2 );
+            answer+=(char)num;
+            s=s.substring( 7 );
+        }
+        return answer;
+    }
+
+    public static void main(String[] args){
+        Scanner in=new Scanner( System.in);
+        sgyj.inflearn.yeji.week2.Solution12 solution12 = new sgyj.inflearn.yeji.week2.Solution12();
+        int n = in.nextInt();
+        in.nextLine();
+        String s = in.nextLine();
+        System.out.println( solution12.solution( n, s ) );
+    }
+}

src/main/java/sgyj/inflearn/study/week2/Solution13.java

@@ -0,0 +1,28 @@
+package sgyj.inflearn.study.week2;
+
+import java.util.ArrayList;
+import java.util.Scanner;
+
+public class Solution13 {
+    public ArrayList<Integer> solution( int n, int[] arr){
+        ArrayList<Integer> answer = new ArrayList<>();
+        answer.add( arr[0] );
+        for(int i=1; i<n; i++){
+            if(arr[i] > arr[i-1]) answer.add( arr[i] );
+        }
+        return answer;
+    }
+
+    public static void main(String[] args){
+        Solution13 solution13 = new Solution13();
+        Scanner kb = new Scanner( System.in );
+        int n = kb.nextInt();
+        int[] arr = new int[n];
+        for ( int i = 0; i < n; i++ ) {
+            arr[i] = kb.nextInt();
+        }
+        for(int x : solution13.solution(n,arr)){
+            System.out.print( x + " " );
+        }
+    }
+}

src/main/java/sgyj/inflearn/study/week2/Solution14.java

@@ -0,0 +1,30 @@
+package sgyj.inflearn.study.week2;
+
+import java.util.Scanner;
+
+public class Solution14 {
+
+    public static int solution(int n, int[] arr){
+        int answer = 1, max=arr[0];
+
+        for(int i=1; i<n; i++){
+            if(arr[i] > max) {
+                answer++;
+                max=arr[i];
+            }
+        }
+
+        return answer;
+    }
+
+    public static void main(String[] args){
+        Scanner in=new Scanner( System.in);
+        int input1 = in.nextInt();
+        int[] ints = new int[input1];
+        for(int i=0; i<input1; i++){
+            ints[i] = in.nextInt();
+        }
+        System.out.print(solution(input1, ints));
+    }
+
+}

src/main/java/sgyj/inflearn/study/week2/Solution15.java

@@ -0,0 +1,42 @@
+package sgyj.inflearn.study.week2;
+
+import java.util.Scanner;
+
+public class Solution15 {
+
+    public static String solution(int n, int[] a, int[] b){
+        String answer = "";
+        for(int i=0; i<n; i++){
+            if(a[i] == b[i]){
+                answer+="D";
+            }else if(a[i] == 1 && b[i] == 3){
+                answer+="A";
+            }else if(a[i] == 2 && b[i] == 1){
+                answer+="A";
+            }else if(a[i] == 3 && b[i] == 2){
+                answer+="A";
+            }else{
+                answer+="B";
+            }
+        }
+
+        return answer;
+    }
+
+
+    public static void main(String[] args){
+        Scanner in=new Scanner( System.in);
+        int input1 = in.nextInt();
+        in.nextLine();
+        int[] input2 = new int[input1];
+        int[] input3 = new int[input1];
+        for(int i=0; i<input1; i++){
+            input2[i] = in.nextInt();
+        }
+        for(int i=0; i<input1; i++){
+            input3[i] = in.nextInt();
+        }
+        String solution = solution( input1, input2, input3 );
+        System.out.println(solution);
+    }
+}

src/main/java/sgyj/inflearn/study/week2/Solution16.java

@@ -0,0 +1,26 @@
+package sgyj.inflearn.study.week2;
+
+import java.util.Scanner;
+
+public class Solution16 {
+
+    public int[] solution(int n){
+        int[] answer = new int[n];
+        answer[0] = 1;
+        answer[1] = 1;
+
+        for(int i=2; i<n; i++){
+            answer[i] = answer[i-2] + answer[i-1];
+        }
+
+        return answer;
+    }
+
+    public static void main(String[] args){
+        Solution16 solution16 = new Solution16();
+        Scanner kb = new Scanner( System.in );
+        int n = kb.nextInt();
+        for(int x : solution16.solution(n)) System.out.print(x + " ");
+
+    }
+}

src/main/java/sgyj/inflearn/study/week2/Solution17.java

@@ -0,0 +1,27 @@
+package sgyj.inflearn.study.week2;
+
+import java.util.Scanner;
+
+public class Solution17 {
+
+    public int solution(int n){
+        int answer = 0;
+        int[] ch = new int[n+1];
+        for(int i=2; i<=n; i++){
+            if(ch[i] == 0){
+                answer++;
+                for(int j=i; j<=n; j=j+1){
+                    ch[j] = 1;
+                }
+            }
+        }
+        return answer;
+    }
+
+    public static void main(String[] args){
+        Solution17 solution17 = new Solution17();
+        Scanner scanner = new Scanner( System.in );
+        int n = scanner.nextInt();
+        System.out.print(solution17.solution(n));
+    }
+}

src/main/java/sgyj/inflearn/study/week2/Solution18.java

@@ -0,0 +1,45 @@
+package sgyj.inflearn.study.week2;
+
+import java.util.ArrayList;
+import java.util.Scanner;
+
+public class Solution18 {
+
+    public boolean isPrime(int num){
+        if(num == 1) return false;
+        for(int i=2; i<num; i++){
+            if(num % i ==0) return false;
+        }
+        return true;
+    }
+
+    public ArrayList<Integer> solution(int n , int[] arr){
+        ArrayList<Integer> answer = new ArrayList<>();
+
+        for(int i=0; i<n; i++){
+            int tmp = arr[i];
+            int res = 0;
+            while(tmp > 0){
+                int t = tmp % 10;
+                res = res * 10 + t;
+                tmp = tmp/10;
+            }
+            if(isPrime(res)) answer.add( res );
+        }
+
+        return answer;
+    }
+
+    public static void main(String[] args){
+        Solution18 solution18 = new Solution18();
+        Scanner scanner = new Scanner( System.in );
+        int n = scanner.nextInt();
+        int[] arr = new int[n];
+        for(int i=0; i<n; i++){
+            arr[i] = scanner.nextInt();
+        }
+        for(int x : solution18.solution(n, arr)){
+            System.out.print(x+" ");
+        }
+    }
+}

src/main/java/sgyj/inflearn/study/week2/Solution19.java

@@ -0,0 +1,34 @@
+package sgyj.inflearn.study.week2;
+
+import java.util.Scanner;
+
+public class Solution19 {
+
+    public int solution(int n, int[] arr){
+        int answer = 0, cnt = 0;
+        for(int i=0; i<n; i++){
+            if(arr[i] == 1){
+                cnt++;
+                answer+=cnt;
+            }else{
+                cnt=0;
+            }
+        }
+
+        return answer;
+    }
+
+    public void main(String[] args){
+        Solution19 solution19 = new Solution19();
+        Scanner scanner = new Scanner( System.in );
+        int n = scanner.nextInt();
+
+        int[] arr = new int[n];
+
+        for(int i=0; i<n; i++){
+            arr[i] = scanner.nextInt();
+        }
+
+        System.out.print(solution19.solution(n, arr));
+    }
+}

src/main/java/sgyj/inflearn/study/week2/Solution20.java

@@ -0,0 +1,30 @@
+package sgyj.inflearn.study.week2;
+
+import java.util.Scanner;
+
+public class Solution20 {
+    public int[] solution(int n, int[] arr){
+        int[] answer = new int[n];
+
+        for(int i=0; i<n; i++){
+            int cnt = 1;
+            for(int j=0; j<n; j++){
+                if(arr[j] > arr[i]) cnt++;
+            }
+            answer[i] = cnt;
+        }
+
+        return answer;
+    }
+
+    public void main(String[] args){
+        Solution20 solution20 = new Solution20();
+        Scanner scanner = new Scanner( System.in );
+        int n = scanner.nextInt();
+        int[] arr = new int[n];
+        for(int i=0; i<n; i++){
+            arr[i] = scanner.nextInt();
+        }
+        for(int x : solution20.solution(n, arr)) System.out.print(x + " ");
+    }
+}