[Programmers 1844]ゲームマップ最短距離(Python)

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問題を解く

コード#コード#

from collections import deque
from collections import defaultdict

def solution(maps):
    n = len(maps)
    m = len(maps[0])
    
    dx = [-1,1,0,0]
    dy = [0,0,-1,1]
    
    graph = defaultdict(list)
    for i,row in enumerate(maps):
        for j,check in enumerate(row):
            if check == 1:
                for k in range(4):
                    nx = i + dx[k]
                    ny = j + dy[k]
                    if 0 <= nx < n and 0 <= ny < m:
                        if maps[nx][ny] == 1:
                            graph[(i,j)].append((nx,ny))
                            graph[(nx,ny)].append((i,j))
   
    def bfs(graph,i,j):
        visit = [[0] * m for _ in range(n)]
        visit[0][0] = 1
        queue = deque()
        queue.append([(i,j),1])

        while queue:
            temp = queue.popleft()
            location, cnt = temp[0], temp[1]
            if location == (n-1,m-1):
                return cnt
	    # 방문 안한 좌표일 때만 체크해준다.
            if location not in visit:
                x, y =location[0], location[1]
                visit[x][y] = 1
		#인근 좌표에 대해서 방문을 해준다.
                if location in graph:
                    next_nodes = list(graph[location])

                    for next_node in next_nodes:
                        x, y =next_node[0], next_node[1]
                        if visit[x][y]== 0:
                            queue.append([next_node,cnt+1])
                            visit[x][y] = 1
    
    answer = bfs(graph,0,0)
    if (answer): return answer
    return -1