結果

問題 No.1316 Maximum Minimum Spanning Tree
コンテスト
ユーザー opt
提出日時 2020-12-08 20:39:49
言語 PyPy3
(7.3.15)
結果
WA  
実行時間 -
コード長 2,478 bytes
コンパイル時間 149 ms
コンパイル使用メモリ 82,376 KB
実行使用メモリ 81,540 KB
最終ジャッジ日時 2024-09-19 22:00:30
合計ジャッジ時間 22,246 ms
ジャッジサーバーID
（参考情報） 		judge2 / 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 WA * 4
other WA * 78
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 # 

# Dinic's algorithm from:
# https://tjkendev.github.io/procon-library/python/max_flow/dinic.html
from collections import deque
class Dinic:
    def __init__(self, N):
        self.N = N
        self.G = [[] for i in range(N)]

    def add_edge(self, fr, to, cap):
        forward = [to, cap, None]
        forward[2] = backward = [fr, 0, forward]
        self.G[fr].append(forward)
        self.G[to].append(backward)

    def add_multi_edge(self, v1, v2, cap1, cap2):
        edge1 = [v2, cap1, None]
        edge1[2] = edge2 = [v1, cap2, edge1]
        self.G[v1].append(edge1)
        self.G[v2].append(edge2)

    def bfs(self, s, t):
        self.level = level = [None]*self.N
        deq = deque([s])
        level[s] = 0
        G = self.G
        while deq:
            v = deq.popleft()
            lv = level[v] + 1
            for w, cap, _ in G[v]:
                if cap and level[w] is None:
                    level[w] = lv
                    deq.append(w)
        return level[t] is not None

    def dfs(self, v, t, f):
        if v == t:
            return f
        level = self.level
        for e in self.it[v]:
            w, cap, rev = e
            if cap and level[v] < level[w]:
                d = self.dfs(w, t, min(f, cap))
                if d:
                    e[1] -= d
                    rev[1] += d
                    return d
        return 0

    def flow(self, s, t):
        flow = 0
        INF = 10**9 + 7
        G = self.G
        while self.bfs(s, t):
            *self.it, = map(iter, self.G)
            f = INF
            while f:
                f = self.dfs(s, t, INF)
                flow += f
        return flow
##########################################


n, m, k = map(int, input().split())
edges = [list(map(int, input().split())) for _ in range(m)]
edges.sort(key=lambda x: x[2])
y = [0] * m

s, t = 0, n+1
ysum = ans = 0

for i, (a, b, c, d) in enumerate(edges):
    g = Dinic(n+2)
    cs = [0] * (n+1)
    for j, (a2, b2, _, _) in enumerate(edges):
        if y[j] > 0:
            g.add_multi_edge(a2, b2, y[j], y[j])
        cs[a2] += y[j]
        cs[b2] += y[j]
    for v in range(1, n+1):
        if v == a or v == b:
            g.add_edge(s, v, 2*k*n)
        elif cs[v] > 0:
            g.add_edge(s, v, cs[v])
        g.add_edge(v, t, 2*k)
    f = g.flow(s, t)
    z = f // 2 - k - ysum
    y[i] = min(z, d)
    ysum += y[i]
    ans += c * y[i]
    print(y[i])

if ysum < k*(n-1):
    ans = -1
print(ans)
0