新城的地下迷宫是一个 3×3 网格。以下DFS代码用于统计从 (0,0) 到 (2,2) 的路径数量(只能向右或向下)。请问 paths 的最终值是多少?
paths = 0
def dfs(x, y, target_x, target_y):
global paths
if x == target_x and y == target_y:
paths += 1
return
if x < target_x: dfs(x + 1, y, target_x, target_y)
if y < target_y: dfs(x, y + 1, target_x, target_y)
dfs(0, 0, 2, 2)
print(paths)
4
6
8
10