[Week05, Week06]

personal/JAEHEE25/PGS/문자열_압축.java

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+import java.util.*;
+
+class Solution {
+    public int solution(String s) {
+        int answer = Integer.MAX_VALUE;
+        int len = 1; //단위
+        int N = s.length();
+
+        while (len <= N) {
+            StringBuilder resultBuilder = new StringBuilder();
+            StringBuilder wordBuilder = new StringBuilder();
+            String prev = "";
+            String word = "";
+            int cnt = 0;
+            for (int i = 0; i <= N; i++) {
+                word = wordBuilder.toString();
+                if (word.length() == len) {
+                    if (prev.equals("")) { //맨 처음일 경우 prev에 저장
+                        prev = word;
+                        cnt++;
+                    } else if (prev.equals(word)) { //연속된 단어일 경우 개수 카운트
+                        cnt++;
+                    } else { //새로운 단어일 경우 이전 단어 기록
+                        if (cnt <= 1) resultBuilder.append(prev);
+                        else resultBuilder.append(cnt + prev);
+                        prev = word;
+                        cnt = 1;
+                    }
+                    wordBuilder = new StringBuilder(); //초기화
+                }
+                if (i < N) wordBuilder.append(s.charAt(i));
+            }
+
+            //마지막 처리
+            if (cnt <= 1) resultBuilder.append(prev);
+            else resultBuilder.append(cnt + prev);
+            resultBuilder.append(wordBuilder.toString()); //남은 글자들
+
+            //정답 구하기
+            answer = Math.min(resultBuilder.length(), answer);
+            len++;
+        }
+
+        return answer;
+    }
+}

weekly/week05/BOJ_14002_가장긴증가하는부분수열4/JAEHEE25.java

@@ -0,0 +1,50 @@
+package week05.BOJ_14002_가장긴증가하는부분수열4;
+
+import java.util.*;
+import java.lang.*;
+import java.io.*;
+
+class BOJ14002 {
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        int N = Integer.parseInt(br.readLine());
+        StringTokenizer st = new StringTokenizer(br.readLine());
+        int[] arr = new int[N];
+        for (int i = 0; i < N; i++) {
+            arr[i] = Integer.parseInt(st.nextToken());
+        }
+
+        int[] dp = new int[N];
+        for (int i = 0; i < N; i++) {
+            dp[i] = 1;
+            for (int j = 0; j < i; j++) {
+                if (arr[j] < arr[i]) {
+                    dp[i] = Math.max(dp[i], dp[j] + 1);
+                }
+            }
+        }
+
+        StringBuilder answer = new StringBuilder();
+        int max = 0;
+        for (int i = 0; i < N; i++) {
+            if (dp[i] > max) {
+                max = dp[i];
+            }
+        }
+        answer.append(max).append("\n");
+
+        Stack<Integer> stack = new Stack<>();
+        for (int i = N - 1; i >= 0; i--) {
+            if (dp[i] == max) {
+                stack.push(arr[i]);
+                max--;
+            }
+        }
+
+        while (!stack.isEmpty()) {
+            answer.append(stack.pop()).append(" ");
+        }
+
+        System.out.println(answer);
+    }
+}

weekly/week05/BOJ_1781_컵라면/JAEHEE25.java

@@ -0,0 +1,43 @@
+package week05.BOJ_1781_컵라면;
+import java.util.*;
+import java.lang.*;
+import java.io.*;
+
+class BOJ1781 {
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        int N = Integer.parseInt(br.readLine());
+        int[][] works = new int[N][2]; //데드라인, 컵라면 수
+        for (int i = 0; i < N; i++) {
+            StringTokenizer st = new StringTokenizer(br.readLine());
+            works[i][0] = Integer.parseInt(st.nextToken());
+            works[i][1] = Integer.parseInt(st.nextToken());
+        }
+
+        Arrays.sort(works, (o1, o2) -> {
+            if (o1[0] == o2[0]) return o2[1] - o1[1];
+            return o1[0] - o2[0];
+        });
+
+        PriorityQueue<Integer> pq = new PriorityQueue<>(); //푼 문제의 컵라면 수 저장
+        for (int i = 0; i < N; i++) {
+
+            //pq 사이즈 == 푼 문제 수 == 사용한 시간과 데드라인 시간 비교
+            if (pq.size() < works[i][0]) {
+                pq.offer(works[i][1]);
+            } else {
+                if (pq.peek() < works[i][1]) { //기존에 풀었던 문제의 컵라면 수보다 크면 교체
+                    pq.poll();
+                    pq.offer(works[i][1]);
+                }
+            }
+        }
+
+        //출력
+        int answer = 0;
+        while (!pq.isEmpty()) {
+            answer += pq.poll();
+        }
+        System.out.println(answer);
+    }
+}

weekly/week05/BOJ_6236_용돈관리/JAEHEE25.java

@@ -0,0 +1,51 @@
+package week05.BOJ_6236_용돈관리;
+
+import java.util.*;
+import java.lang.*;
+import java.io.*;
+
+class BOJ6236 {
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st = new StringTokenizer(br.readLine());
+        int N = Integer.parseInt(st.nextToken());
+        int M = Integer.parseInt(st.nextToken());
+        int[] money = new int[N];
+        int max = 0;
+        for (int i = 0; i < N; i++) {
+            money[i] = Integer.parseInt(br.readLine());
+            max = Math.max(money[i], max); //최대 금액을 최솟값으로 설정
+        }
+
+        int answer = 0;
+        int left = max;
+        int right = 10000 * 100000;
+        while (left <= right) {
+            int K = (left + right) / 2;
+
+            //결과 계산
+            int result = getWithdrawCnt(money, K, M);
+
+            if (M >= result) {
+                answer = K;
+                right = K - 1;
+            } else {
+                left = K + 1;
+            }
+        }
+        System.out.println(answer);
+    }
+
+    static int getWithdrawCnt(int[] money, int K, int M) {
+        int withdrawCnt = 1;
+        int now = K;
+        for (int i = 0; i < money.length; i++) {
+            if (money[i] > now) { //모자라면 K원 인출
+                withdrawCnt++;
+                now = K;
+            }
+            now -= money[i];
+        }
+        return withdrawCnt;
+    }
+}

weekly/week06/BOJ_17070_파이프옮기기1/JAEHEE25.java

@@ -0,0 +1,63 @@
+package week06.BOJ_17070_파이프옮기기1;
+
+import java.util.*;
+import java.lang.*;
+import java.io.*;
+
+class BOJ17070 {
+    static final int WALL = 1;
+    static int answer = 0;
+    static int N;
+    static int[][] house;
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        N = Integer.parseInt(br.readLine());
+        house = new int[N][N];
+        for (int i = 0; i < N; i++) {
+            StringTokenizer st = new StringTokenizer(br.readLine());
+            for (int j = 0; j < N; j++) {
+                house[i][j] = Integer.parseInt(st.nextToken());
+            }
+        }
+        move(0, 1, 'H'); //0,1에서 시작
+        System.out.println(answer);
+    }
+
+    static void move(int x, int y, char dir) {
+        //각 dir에 따라 갈 방법이 없으면 return
+        if (dir == 'H' || dir == 'V') {
+            if (!isPossible(x, y) || house[x][y] == WALL) {
+                return;
+            }
+        } else {
+            if (!isPossible(x, y) || !isPossible(x-1, y) || !isPossible(x, y-1) ||
+                   house[x][y] == WALL || house[x-1][y] == WALL || house[x][y-1] == WALL) {
+                return;
+            }
+        }
+
+        if (x == N - 1 && y == N - 1) { //도착
+            answer++;
+            return;
+        }
+
+        if (dir == 'H') { //가로 이동
+            move(x, y+1, 'H'); //1번
+            move(x+1, y+1, 'D'); //2번
+
+        } else if (dir == 'V') { //세로 이동
+            move(x+1, y, 'V'); //1번
+            move(x+1, y+1, 'D'); //2번
+
+        } else { //대각선 이동
+            move(x, y+1, 'H'); //1번
+            move(x+1, y, 'V'); //2번
+            move(x+1, y+1, 'D'); //3번
+        }
+
+    }
+
+    static boolean isPossible(int x, int y) {
+        return x >= 0 && x < N && y >= 0 && y < N;
+    }
+}

weekly/week06/BOJ_2580_스도쿠/JAEHEE25.java

@@ -0,0 +1,80 @@
+package week06.BOJ_2580_스도쿠;
+import java.util.*;
+import java.lang.*;
+import java.io.*;
+
+class BOJ2580 {
+    static int N = 9;
+    static int[][] board;
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        board = new int[N][N];
+        for (int i = 0; i < N; i++) {
+            StringTokenizer st = new StringTokenizer(br.readLine());
+            for (int j = 0; j < N; j++) {
+                board[i][j] = Integer.parseInt(st.nextToken());
+            }
+        }
+        sudoku(0, 0);
+    }
+
+    static void sudoku(int x, int y) {
+        if (y == N) { //하나의 행 모두 확인
+            sudoku(x + 1, 0); //다음 행으로 이동
+            return;
+        }
+
+        if (x == N) { //모든 칸 확인 -> 출력
+            StringBuilder sb = new StringBuilder();
+            for(int i = 0; i < N; i++){
+                for(int j = 0; j < N; j++){
+                    sb.append(board[i][j]).append(' ');
+                }
+                sb.append("\n");
+            }
+            System.out.println(sb);
+            System.exit(0); //하나만 출력해야하기 때문에 시스템 종료
+        }
+
+        if (board[x][y] == 0) { //빈칸일 경우
+            for (int num = 1; num <= N; num++) { //1~9 중 가능한 수 찾기
+                if (checkPossible(x, y, num)) {
+                    board[x][y] = num; //가능한 수 빈칸에 넣기
+                    sudoku(x, y + 1); //다음 칸 확인
+                    board[x][y] = 0; //다시 빈 칸으로 처리
+                }
+            }
+        } else { //빈칸이 아닐 경우 다음 칸 확인
+            sudoku(x, y + 1);
+        }
+    }
+
+    static boolean checkPossible(int x, int y, int value) { //value가 있는지 검사
+        //행 검사
+        for (int i = 0; i < N; i++) {
+            if (board[x][i] == value) {
+                return false;
+            }
+        }
+
+        //열 검사
+        for (int i = 0; i < N; i++) {
+            if (board[i][y] == value) {
+                return false;
+            }
+        }
+
+        //정사각형 검사
+        int sx = (x / 3) * 3;
+        int sy = (y / 3) * 3;
+        for (int i = sx; i < sx + 3; i++) {
+    		for (int j = sy; j < sy + 3; j++) {
+    			if (board[i][j] == value) {
+    				return false;
+    			}
+    		}
+    	}
+        return true;
+    }
+
+}

weekly/week06/PGS_요격시스템/JAEHEE25.java

@@ -0,0 +1,24 @@
+package week06.PGS_요격시스템;
+
+import java.util.*;
+class Solution {
+    public int solution(int[][] targets) {
+        int answer = 0;
+        Arrays.sort(targets, (o1, o2) -> o1[0] - o2[0]);
+
+        int start = -1; //현재 요격 미사일의 범위
+        int end = 100_000_001;
+        for (int i = 0; i < targets.length; i++) {
+            if (targets[i][0] >= end) {
+                answer++;
+                start = -1;
+                end = 100_000_001;
+            }
+            start = Math.max(start, targets[i][0]);
+            end = Math.min(end, targets[i][1]);
+        }
+
+        answer++;
+        return answer;
+    }
+}