結果

問題 No.1301 Strange Graph Shortest Path
ユーザー eijiroueijirou
提出日時 2020-11-27 22:57:17
言語 PyPy3
(7.3.15)
結果
WA  
実行時間 -
コード長 1,729 bytes
コンパイル時間 245 ms
コンパイル使用メモリ 82,368 KB
実行使用メモリ 111,772 KB
最終ジャッジ日時 2024-07-26 20:12:25
合計ジャッジ時間 20,259 ms
ジャッジサーバーID
（参考情報） 		judge2 / judge5
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ファイルパターン 結果
sample AC * 2
other AC * 28 WA * 5
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 # 

from heapq import heappush, heappop
from sys import stdin
input = stdin.readline
inf = 1 << 60

def main():
    n, m = map(int, input().split())
    edges = [[] for _ in range(n)]
    for _ in range(m):
        u, v, c, d = map(int, input().split())
        edges[u-1].append([v-1, c, d])
        edges[v-1].append([u-1, c, d])
    for i in range(n):
        edges[i].sort(key=lambda x: x[0])

    # dijkstra
    dist = [inf] * n
    dist[0] = 0
    prev = [-1] * n
    heap = []
    heappush(heap, (0, 0))
    while heap:
        cost, u = heappop(heap)
        if u == n-1:
            break
        if dist[u] < cost:
            continue
        for v, c, d in edges[u]:
            if cost + c < dist[v]:
                dist[v] = cost + c
                prev[v] = u
                heappush(heap, (cost+c, v))
    dist1 = dist[n-1]

    def binary_search(u, v):
        left = 0
        right = len(edges[u]) - 1
        while left < right:
            center = (left + right) // 2
            if edges[u][center][0] < v:
                left = center + 1
            else:
                right = center
        edges[u][left][1], edges[u][left][2] = edges[u][left][2], edges[u][left][1]

    u = n-1
    while u > 0:
        v = prev[u]
        binary_search(u, v)
        binary_search(v, u)
        u = v

    # dijkstra
    dist = [inf] * n
    dist[0] = 0
    heap = []
    heappush(heap, (0, 0))
    while heap:
        cost, u = heappop(heap)
        if u == n-1:
            break
        if dist[u] < cost:
            continue
        for v, c, d in edges[u]:
            if cost + c < dist[v]:
                dist[v] = cost + c
                heappush(heap, (cost+c, v))

    print(dist1 + dist[n-1])

main()
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