059 - Many Graph Queries（★7） https://atcoder.jp/contests/typical90/tasks/typical90_bg

typical90_bg.py

import sys

input = sys.stdin.readline
N, M, Q = map(int, input().split())
G = [[] for _ in range(N)]
for _ in range(M):
    x, y = map(lambda n: int(n) - 1, input().split())
    G[y].append(x)              # 子が親へのポインタを持つようなグラフ
ans = []
for i in range(N):
    bs = 1 << i
    for v in G[i]:
        bs |= ans[v]
    ans.append(bs)
for _ in range(Q):
    a, b = map(lambda n: int(n) - 1, input().split())
    if (ans[b] >> a) & 1:
        print("Yes")
    else:
        print("No")