Merge branch 'week1'

Author: spring0913

week1/BOJ_11497(통나무 건너뛰기).java

@@ -0,0 +1,38 @@
+import java.io.*;
+import java.util.*;
+
+public class Main {
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        int T = Integer.parseInt(br.readLine());
+        StringBuffer sb = new StringBuffer();
+        for(int i=0; i<T; i++) {
+            int N = Integer.parseInt(br.readLine());
+            int[] arr = new int[N];
+            StringTokenizer st = new StringTokenizer(br.readLine());
+            for(int j=0; j<N; j++) {
+                arr[j] = Integer.parseInt(st.nextToken());
+            }
+            Arrays.sort(arr);
+
+            Deque<Integer> q = new LinkedList<>();
+            q.add(arr[N-1]);
+            for(int j=N-2; j>=1; j-=2) {
+                q.addFirst(arr[j]);
+                q.addLast(arr[j-1]);
+            }
+            if(N%2 == 0) {
+                q.addFirst(arr[0]);
+            }
+
+            int answer = Math.abs(q.getFirst() - q.getLast());
+            for(int j=0; j<N-1; j++) {
+                int num = q.removeFirst();
+                answer = Math.max(answer, Math.abs(num-q.getFirst()));
+            }
+            sb.append(answer).append('\n');
+        }
+        System.out.println(sb.toString());
+    }
+}

week1/BOJ_1455(뒤집기 II).java

@@ -0,0 +1,40 @@
+import java.io.*;
+
+public class Main {
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        String[] num = br.readLine().split(" ");
+        int N = Integer.parseInt(num[0]);
+        int M = Integer.parseInt(num[1]);
+        int[][] coin = new int[N][M];
+        for (int i = 0; i < N; i++) {
+            String input = br.readLine();
+            for (int j = 0; j < M; j++) {
+                coin[i][j] = input.charAt(j) - '0';
+            }
+        }
+        int count = 0;
+        for (int i = N-1; i >= 0; i--) {
+            for (int j = M-1; j >= 0; j--) {
+                if(coin[i][j] == 1) {
+                    flipCoin(coin, i, j);
+                    count++;
+                }
+            }
+        }
+        System.out.println(count);
+    }
+
+    public static void flipCoin(int[][] coin, int a, int b) {
+        for(int i=0; i<=a; i++) {
+            for(int j=0; j<=b; j++) {
+                if(coin[i][j] == 0) {
+                    coin[i][j] = 1;
+                }else {
+                    coin[i][j] = 0;
+                }
+            }
+        }
+    }
+}

week1/BOJ_15903(카드 합체 놀이).java

@@ -0,0 +1,35 @@
+import java.io.*;
+import java.util.*;
+
+public class Main {
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        String[] input = br.readLine().split(" ");
+        int n = Integer.parseInt(input[0]);
+        int m = Integer.parseInt(input[1]);
+
+        StringTokenizer st = new StringTokenizer(br.readLine());
+        long[] cards = new long[n];
+        for(int i=0; i<n; i++) {
+            cards[i] = Integer.parseInt(st.nextToken());
+        }
+        Arrays.sort(cards);
+        for(int i=0; i<m; i++) {
+            mergeCard(cards);
+        }
+        long sum = 0;
+        for(long num : cards) {
+            sum += num;
+        }
+        System.out.println(sum);
+    }
+
+    public static void mergeCard(long[] cards) {
+        long num = cards[0] + cards[1];
+        cards[0] = cards[1] = num;
+        if(cards.length >= 3 && num > cards[2]) {
+            Arrays.sort(cards);
+        }
+    }
+}

week1/BOJ_1783(병든 나이트).java

@@ -0,0 +1,22 @@
+import java.io.*;
+
+public class Main {
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        String[] input = br.readLine().split(" ");
+        int N = Integer.parseInt(input[0]);
+        int M = Integer.parseInt(input[1]);
+        if(N == 1) {
+            System.out.println("1");
+        }else if(N == 2) {
+            System.out.println(Math.min(4, (M+1)/2));
+        }else {
+            if(M <= 6) {
+                System.out.println(Math.min(4, M));
+            }else {
+                System.out.println(M-2);
+            }
+        }
+    }
+}

week1/BOJ_2785(체인).java

@@ -0,0 +1,29 @@
+import java.io.*;
+import java.util.*;
+
+public class Main {
+
+    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());
+        PriorityQueue<Integer> q = new PriorityQueue<>();
+        for(int i=0; i<N; i++) {
+            q.offer(Integer.parseInt(st.nextToken()));
+        }
+
+        int count = 0;
+        int link = q.size() - 1;
+        while(true) {
+            int chain = q.peek();
+            if(link > chain) {
+                link -= chain + 1;
+                count += q.poll();
+            }else {
+                count += link;
+                break;
+            }
+        }
+        System.out.println(count);
+    }
+}

week1/BOJ_2885(초콜릿 식사).java

@@ -0,0 +1,27 @@
+import java.io.*;
+
+public class Main {
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        int K = Integer.parseInt(br.readLine());
+        int square = 1;
+        while(square < K) {
+            square *= 2;
+            if(square == K) {
+                System.out.println(square + " 0");
+                return;
+            }
+        }
+        int count = 0;
+        int num = square;
+        while(K >= 1) {
+            num /= 2;
+            if(num <= K) {
+                K -= num;
+            }
+            count++;
+        }
+        System.out.println(square + " " + count);
+    }
+}