2025-02-04

tgyuuAn/DFS/내리막 길.py

@@ -0,0 +1,37 @@
+import sys
+sys.setrecursionlimit(10**6)
+
+def input(): return sys.stdin.readline().rstrip()
+
+M, N = map(int, input().split())
+board = [ list(map(int, input().split())) for _ in range(M) ]
+
+dy = [-1, 1, 0, 0]
+dx = [0, 0, -1, 1]
+dp = [[-1 for _ in range(N)] for _ in range(M)]
+
+def dfs(now):
+    if now == (N-1, M-1):
+        return 1
+
+    col, row = now
+    now_value = board[row][col]
+
+    if dp[row][col] != -1:
+        return dp[row][col]
+
+    temp = 0    
+    for dir in range(4):
+        new_col = col + dx[dir]
+        new_row = row + dy[dir]
+
+        if new_col < 0 or new_col > N-1: continue
+        if new_row < 0 or new_row > M-1: continue
+        if board[new_row][new_col] >= now_value: continue
+
+        temp += dfs((new_col,new_row))
+
+    dp[row][col] = temp
+    return dp[row][col]
+
+print(dfs((0,0)))

tgyuuAn/README.md

@@ -89,4 +89,5 @@
 | 85차시 | 2025.01.09 |  다익스트라 + 이분 탐색 | <a href="https://www.acmicpc.net/problem/1800">인터넷 설치</a> | https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/264
 | 86차시 | 2025.01.16 |  이분 탐색  | <a href="https://www.acmicpc.net/problem/1114">통나무 자르기</a> | https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/265
 | 87차시 | 2025.01.31 |  그리디  | <a href="https://www.acmicpc.net/problem/8980">택배</a> | https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/268
+| 88차시 | 2025.02.04 |  DFS + DP  | <a href="https://www.acmicpc.net/problem/1520">내리막 길</a> | https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/269
 ---