結果

問題 No.168 ものさし
ユーザー rpy3cpp
提出日時 2015-05-21 12:34:25
言語 Python3
(3.13.1 + numpy 2.2.1 + scipy 1.14.1)
結果
AC  
実行時間 444 ms / 2,000 ms
コード長 1,927 bytes
コンパイル時間 145 ms
コンパイル使用メモリ 12,928 KB
実行使用メモリ 46,464 KB
最終ジャッジ日時 2024-12-24 07:09:04
合計ジャッジ時間 4,472 ms
ジャッジサーバーID
（参考情報） 		judge3 / judge4
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 4
other AC * 19
権限があれば一括ダウンロードができます

ソースコード

diff # 

import heapq


def read_data():
    N = int(input())
    ps = [list(map(int, input().split())) for i in range(N)]
    return N, ps


def solve(N, ps):
    dist = set_dist(ps)
    tick = 10
    start = 0
    goal = N - 1
    dist_s = [dist[start][v] for v in range(N)]
    dist_g = [dist[goal][v] for v in range(N)]
    pq_s = [(dist_s[v], v) for v in range(1, N)]
    pq_g = [(dist_g[v], v) for v in range(0, N - 1)]
    heapq.heapify(pq_s)
    heapq.heapify(pq_g)
    max_scale2 = 0
    found = False
    while not found:
        d_s, vs = get_next(pq_s, dist_s)
        d_g, vg = get_next(pq_g, dist_g)
        if d_s < d_g:
            if d_s > max_scale2:
                max_scale2 = d_s
            found = process(dist_s, dist_g, pq_s, vs, dist[vs])
        else:
            if d_g > max_scale2:
                max_scale2 = d_g
            found = process(dist_g, dist_s, pq_g, vg, dist[vg])
    return square_round(max_scale2, tick)


def set_dist(ps):
    N = len(ps)
    dist = [[0] * N for v in range(N)]
    for i in range(N-1):
        x0, y0 = ps[i]
        for j in range(i + 1, N):
            x1, y1 = ps[j]
            d = (x0 - x1) ** 2 + (y0 - y1) ** 2
            dist[i][j] = d
            dist[j][i] = d
    return dist


def get_next(pq, dist_x):
    d, v = pq[0]
    while not dist_x[v]:
        heapq.heappop(pq)
        d, v = pq[0]
    return d, v


def process(dist_0, dist_1, pq_0, v0, dist_v0):
    heapq.heappop(pq_0)
    if not dist_1[v0]:
        return True
    dist_0[v0] = 0
    for new_v, (d, new_d) in enumerate(zip(dist_0, dist_v0)):
        if new_d < d:
            heapq.heappush(pq_0, (new_d, new_v))
            dist_0[new_v] = new_d
    return False


def square_round(x_sq, tick):
    x = x_sq ** 0.5
    x_int = (int(x) // tick) * tick
    if x_int ** 2 < x_sq:
        x_int += tick
    return x_int


if __name__ == '__main__':
    N, ps = read_data()
    print(solve(N, ps))
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