結果

問題 No.2328 Build Walls
コンテスト
ユーザー gew1fw
提出日時 2025-06-12 15:18:19
言語 PyPy3
(7.3.15)
結果
MLE  
実行時間 -
コード長 3,582 bytes
コンパイル時間 193 ms
コンパイル使用メモリ 82,680 KB
実行使用メモリ 555,432 KB
最終ジャッジ日時 2025-06-12 15:18:29
合計ジャッジ時間 6,966 ms
ジャッジサーバーID
（参考情報） 		judge4 / judge1
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 * 3
other AC * 10 MLE * 1 -- * 23
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 sys
from collections import deque

class Edge:
    def __init__(self, to, rev, capacity):
        self.to = to
        self.rev = rev
        self.capacity = capacity

class Dinic:
    def __init__(self, n):
        self.size = n
        self.graph = [[] for _ in range(n)]
    
    def add_edge(self, fr, to, cap):
        forward = Edge(to, len(self.graph[to]), cap)
        backward = Edge(fr, len(self.graph[fr]), 0)
        self.graph[fr].append(forward)
        self.graph[to].append(backward)
    
    def bfs_level(self, s, t, level):
        q = deque()
        level[:] = [-1] * self.size
        level[s] = 0
        q.append(s)
        while q:
            v = q.popleft()
            for edge in self.graph[v]:
                if edge.capacity > 0 and level[edge.to] == -1:
                    level[edge.to] = level[v] + 1
                    q.append(edge.to)
                    if edge.to == t:
                        return  # early return
    
    def dfs_flow(self, v, t, flow, level, ptr):
        if v == t:
            return flow
        while ptr[v] < len(self.graph[v]):
            edge = self.graph[v][ptr[v]]
            if edge.capacity > 0 and level[v] < level[edge.to]:
                min_flow = min(flow, edge.capacity)
                result = self.dfs_flow(edge.to, t, min_flow, level, ptr)
                if result > 0:
                    edge.capacity -= result
                    self.graph[edge.to][edge.rev].capacity += result
                    return result
            ptr[v] += 1
        return 0
    
    def max_flow(self, s, t):
        flow = 0
        level = [-1] * self.size
        while True:
            self.bfs_level(s, t, level)
            if level[t] == -1:
                return flow
            ptr = [0] * self.size
            while True:
                f = self.dfs_flow(s, t, float('inf'), level, ptr)
                if f == 0:
                    break
                flow += f
            level = [-1] * self.size
        return flow

def main():
    H, W = map(int, sys.stdin.readline().split())
    A = []
    for _ in range(H-2):
        row = list(map(int, sys.stdin.readline().split()))
        A.append(row)
    
    INF = 10**18
    sum_A = 0
    for row in A:
        for a in row:
            if a != -1:
                sum_A += a
    
    source = 2 * H * W
    sink = source + 1
    size = 2 * H * W + 2
    dinic = Dinic(size)
    
    for i in range(1, H+1):
        for j in range(1, W+1):
            u_in = (i-1)*W + (j-1)
            u_out = u_in + H*W
            
            if i == 1 or i == H:
                dinic.add_edge(u_in, u_out, INF)
            else:
                a = A[i-2][j-1]
                if a == -1:
                    cap = INF
                else:
                    cap = a
                dinic.add_edge(u_in, u_out, cap)
            
            dirs = [(-1,0), (1,0), (0,-1), (0,1)]
            for dx, dy in dirs:
                ni = i + dx
                nj = j + dy
                if 1 <= ni <= H and 1 <= nj <= W:
                    v_in = (ni-1)*W + (nj-1)
                    dinic.add_edge(u_out, v_in, INF)
    
    for j in range(1, W+1):
        u_in = (0)*W + (j-1)
        dinic.add_edge(source, u_in, INF)
    
    for j in range(1, W+1):
        u_out = (H-1)*W + (j-1) + H*W
        dinic.add_edge(u_out, sink, INF)
    
    max_flow = dinic.max_flow(source, sink)
    
    if max_flow > sum_A:
        print(-1)
    elif max_flow == 0:
        print(0)
    else:
        print(max_flow)

if __name__ == '__main__':
    main()
0