Merge pull request #33 from AlgorithmWithGod/suyeun84

[20250204] BOJ / 골드4 / 파이프 옮기기2 / 김수연

Author: ShinHeeEul

suyeun84/202502/04 BOJ G4 파이프 옮기기2.md

@@ -0,0 +1,48 @@
+```java
+import java.util.*;
+import java.io.*;
+
+class Solution
+{
+    public static void main(String[] args) throws Exception{
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st = new StringTokenizer(br.readLine());
+
+        int N = Integer.parseInt(st.nextToken());
+        long answer = 0;
+        int[][] board = new int[N][N];
+        long[][][] dp = new long[N][N][3];
+        for (int i = 0; i < N; i++) {
+        	st = new StringTokenizer(br.readLine());
+        	for (int j = 0; j < N; j++) {
+        		board[i][j] = Integer.parseInt(st.nextToken());
+        	}
+        }
+        dp[0][1][0] = 1;
+        if(board[1][2] == 0 && board[0][2] == 0 && board[1][1] == 0) dp[1][2][2] = 1;
+        for (int i = 2; i < N; i++) {
+        	if(board[0][i] == 0) dp[0][i][0] = dp[0][i-1][0];
+        	if (i == 2) {
+        		if(board[i][2] == 0) dp[2][2][1] = dp[1][2][2];
+        	} else {
+        		if(board[i][2] == 0) dp[i][2][1] = dp[i-1][2][1];
+        	}
+        }
+        
+        for (int i = 1; i < N; i++) {
+        	for (int j = 3; j < N; j++) {
+        		if (board[i][j] == 1) continue;
+        		dp[i][j][0] = dp[i][j-1][0] + dp[i][j-1][2];
+        		dp[i][j][1] = dp[i-1][j][1] + dp[i-1][j][2];
+        		if (board[i-1][j] == 0 && board[i][j-1] == 0)
+        			dp[i][j][2] = dp[i-1][j-1][0] + dp[i-1][j-1][1] + dp[i-1][j-1][2];
+        	}
+        }
+        for (int i = 0; i < 3; i++) {
+        	answer += dp[N-1][N-1][i];
+        }
+        System.out.println(answer);
+    }
+}
+
+```