출발지, 도착지에 따라. BFS로 거리구하면 끝. import sys input = sys.stdin.readline from collections import defaultdict,deque def Distance(a,b): queue = deque() queue.append(a) visited = [False]*(N+1) visited[a] = True target_dist = [0]*(N+1) while queue: v = queue.popleft() if v==b: print(target_dist[v]) return for next,dist in graph[v]: if not visited[next]: queue.append(next) visited[next] = True target_dist[n..