[BOJ] 파이프 옮기기 / 골드5 / 60분

Author: 최재익

jaeik/week8/파이프옮기기/BOJ_17070.java

@@ -0,0 +1,82 @@
+package week8.파이프옮기기;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.StringTokenizer;
+
+public class BOJ_17070 {
+    static int count = 0;
+    static int N;
+    static int[][] map;
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st;
+
+        N = Integer.parseInt(br.readLine());
+        map = new int[N+1][N+1];
+        for(int i=1; i<=N; i++){
+            st = new StringTokenizer(br.readLine());
+            for(int j=1; j<=N; j++){
+                map[i][j] = Integer.parseInt(st.nextToken());
+            }
+        }
+
+        count = 0;
+        dfs(1, 2, 0, 1);
+
+        System.out.println(count);
+    }
+
+    static void dfs(int row, int col, int rowDir, int colDir){
+        if(row==N && col==N){
+            count++;
+            return;
+        }
+
+        List<int[]> nextDir = getNextDir(rowDir, colDir);
+
+        for(int i=0; i<nextDir.size(); i++){
+            int nextRowDir = nextDir.get(i)[0];
+            int nextColDir = nextDir.get(i)[1];
+            int nextRow = row + nextRowDir;
+            int nextCol = col + nextColDir;
+
+            if(nextRow<1 || nextCol<1 || nextRow>N || nextCol>N)continue;
+            if(isDiag(nextRowDir, nextColDir)){
+                if(map[nextRow][nextCol]==1)continue;
+                if(map[nextRow-1][nextCol]==1)continue;
+                if(map[nextRow][nextCol-1]==1)continue;
+            }
+            else{
+                if(map[nextRow][nextCol]==1)continue;
+            }
+
+            dfs(nextRow, nextCol, nextRowDir, nextColDir);
+        }
+    }
+
+    static boolean isDiag(int rowDir, int colDir){
+        return (rowDir!=0&&colDir!=0);
+    }
+
+    static List<int[]> getNextDir(int rowDir, int colDir){
+        List<int[]> nextDir = new ArrayList<>();
+
+        //대각선으로 움직이는 경우
+        if(rowDir!=0&&colDir!=0){
+            nextDir.add(new int[]{rowDir, colDir});
+            nextDir.add(new int[]{rowDir, 0});
+            nextDir.add(new int[]{0, colDir});
+        }
+        //row 또는 col이 움직이는 경우
+        else {
+            nextDir.add(new int[]{rowDir, colDir});
+            nextDir.add(new int[]{1, 1});
+        }
+
+        return nextDir;
+    }
+}