Min: 12월 4주차 문제 풀이

12월/4주차/[BOJ] 세 번 이내에 사과를 먹자/Min.java

@@ -0,0 +1,63 @@
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.StringTokenizer;
+
+class Min {
+    static int[] dx = {1, -1, 0, 0};
+    static int[] dy = {0, 0, 1, -1};
+    static boolean[][] visited;
+    static int[][] arr;
+    static int answer;
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        arr = new int[5][5];
+        StringTokenizer str;
+        for(int i = 0; i < 5; i++) {
+            str = new StringTokenizer(br.readLine());
+            for(int j = 0; j < 5; j++) {
+                arr[i][j] = Integer.parseInt(str.nextToken());
+            }
+        }
+        str = new StringTokenizer(br.readLine());
+        int a = Integer.parseInt(str.nextToken());
+        int b = Integer.parseInt(str.nextToken());
+        visited = new boolean[5][5];
+        int apple = arr[a][b] == 1 ? 1 : 0;
+        answer = 0;
+        visited[a][b] = true;
+        dfs(a, b, 0, apple);
+        System.out.println(answer);
+    }
+
+    private static void dfs(int col, int row, int move, int apple) {
+        if(apple >= 2) {
+            answer = 1;
+            return;
+        }
+        if(move == 3) return;
+
+
+        for(int i = 0; i < 4; i++) {
+            int nx = col + dx[i];
+            int ny = row + dy[i];
+
+            if(isValid(nx, ny) && !visited[nx][ny]) {
+                visited[col][row] = true;
+                if(arr[nx][ny] == 1) {
+                    dfs(nx, ny, move + 1, apple + 1);
+                }else if(arr[nx][ny] == 0){
+                    dfs(nx, ny, move + 1, apple);
+                }
+                visited[nx][ny] = false;
+            }
+        }
+    }
+
+    private static boolean isValid(int x, int y) {
+        if(x >= 0 && x < 5 && y >= 0 && y < 5 && arr[x][y] != -1) {
+            return true;
+        }
+        return false;
+    }
+}

12월/4주차/[BOJ] 스피카/Min.java

@@ -0,0 +1,41 @@
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.ArrayList;
+import java.util.StringTokenizer;
+
+public class Min {
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        ArrayList<ArrayList<Integer>> list = new ArrayList<>();
+        for(int i = 0; i <= 12; i++) {
+            list.add(new ArrayList<>());
+        }
+
+        for(int i = 0; i < 12; i++) {
+            StringTokenizer str = new StringTokenizer(br.readLine());
+            int a = Integer.parseInt(str.nextToken());
+            int b = Integer.parseInt(str.nextToken());
+            list.get(a).add(b);
+            list.get(b).add(a);
+        }
+
+        for(int i = 1; i <= 12; i++) {
+            int total = 0;
+            if(list.get(i).size() == 3) {
+                int a = list.get(i).get(0);
+                total += list.get(a).size();
+                int b = list.get(i).get(1);
+                total += list.get(b).size();
+                int c = list.get(i).get(2);
+                total += list.get(c).size();
+
+                if(total == 6) {
+                    System.out.println(i);
+                    return;
+                }
+
+            }
+        }
+    }    
+}

12월/4주차/[BOJ] 주난의 난/Min.java

@@ -0,0 +1,67 @@
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.PriorityQueue;
+import java.util.StringTokenizer;
+
+public class Min {
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer str = new StringTokenizer(br.readLine());
+        int N = Integer.parseInt(str.nextToken());
+        int M = Integer.parseInt(str.nextToken());
+        String[][] arr = new String[N][M];
+        str = new StringTokenizer(br.readLine());
+        int x1 = Integer.parseInt(str.nextToken()) - 1;
+        int y1 = Integer.parseInt(str.nextToken()) - 1;
+        int x2 = Integer.parseInt(str.nextToken()) - 1;
+        int y2 = Integer.parseInt(str.nextToken()) - 1;
+
+        for(int i = 0; i < N; i++) {
+            arr[i] = br.readLine().split("");
+        }
+
+        boolean[][] visited = new boolean[N][M];
+        PriorityQueue<int[]> pq = new PriorityQueue<>((o1, o2) -> o1[2] - o2[2]);
+        pq.offer(new int[]{x1, y1, 0});
+        int[] dx = {1, -1, 0, 0};
+        int[] dy = {0, 0, 1, -1};
+
+        while(!pq.isEmpty()) {
+            int[] tmp = pq.poll();
+            int x = tmp[0];
+            int y = tmp[1];
+            int cnt = tmp[2];
+
+            if(visited[x][y]) continue;
+            visited[x][y] = true;
+
+            if(x == x2 && y == y2) {
+                System.out.println(cnt);
+                return;
+            }
+
+            for(int i = 0; i < 4; i++) {
+                int nx = x + dx[i];
+                int ny = y + dy[i];
+                if(!isValid(nx, ny, N, M) || visited[nx][ny]) continue;
+
+                if(nx == x2 && ny == y2) {
+                    System.out.println(cnt + 1);
+                    return;
+                }
+
+                if (arr[nx][ny].equals("1")) {
+                    pq.offer(new int[]{nx, ny, cnt + 1});
+                } else { 
+                    pq.offer(new int[]{nx, ny, cnt});
+                }
+
+            }
+        }
+    }
+
+    private static boolean isValid(int x, int y, int N, int M) {
+        return x >= 0 && x < N && y >= 0 && y < M;
+    }
+}