https://www.acmicpc.net/problem/27971import sysfrom collections import dequeinput = sys.stdin.readlinen,m,a,b = map(int, input().split())dp = [0] * (n+1)visited = [False] * (n+1)for _ in range(m): l,r = map(int, input().split()) for i in range(l, r+1): visited[i] = True # 닫힌구간 방문처리dp[n] = 0q = deque()q.append(n)while q: value = q.popleft() if value == 0: break for i ..