結果

問題 No.957 植林
ユーザー lam6er
提出日時 2025-03-26 15:54:35
言語 PyPy3
(7.3.15)
結果
TLE  
実行時間 -
コード長 3,838 bytes
コンパイル時間 353 ms
コンパイル使用メモリ 82,364 KB
実行使用メモリ 187,960 KB
最終ジャッジ日時 2025-03-26 15:55:42
合計ジャッジ時間 17,764 ms
ジャッジサーバーID
(参考情報)
judge3 / judge1
このコードへのチャレンジ
(要ログイン)
ファイルパターン 結果
sample AC * 3
other AC * 15 TLE * 1 -- * 29
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 MaxFlow:
    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
        return
        
    def dfs_flow(self, v, t, upTo, iter_, level):
        if v == t:
            return upTo
        for i in range(iter_[v], len(self.graph[v])):
            edge = self.graph[v][i]
            if edge.capacity > 0 and level[v] < level[edge.to]:
                d = self.dfs_flow(edge.to, t, min(upTo, edge.capacity), iter_, level)
                if d > 0:
                    edge.capacity -= d
                    self.graph[edge.to][edge.rev].capacity += d
                    return d
            iter_[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
            iter_ = [0] * self.size
            while True:
                f = self.dfs_flow(s, t, float('inf'), iter_, level)
                if f == 0:
                    break
                flow += f
            level = [-1] * self.size
        return flow

def main():
    H, W = map(int, sys.stdin.readline().split())
    G = []
    for _ in range(H):
        G.append(list(map(int, sys.stdin.readline().split())))
    R = list(map(int, sys.stdin.readline().split()))
    C = list(map(int, sys.stdin.readline().split()))
    
    # Compute A and B
    A = []
    for i in range(H):
        total = sum(G[i])
        A.append(R[i] - total)
    
    B = []
    for j in range(W):
        total = sum(G[i][j] for i in range(H))
        B.append(C[j] - total)
    
    # Compute the sum of positive terms for maximum possible
    total_positive = 0
    
    # Create nodes: rows (0..H-1), cols (H..H+W-1), edges (H+W..H+W+H*W-1)
    edge_node_start = H + W
    total_nodes = edge_node_start + H * W
    S = total_nodes
    T = S + 1
    mf = MaxFlow(T + 1)
    
    INF = 1 << 60
    
    # Add row nodes
    for i in range(H):
        a = A[i]
        if a > 0:
            mf.add_edge(S, i, a)
            total_positive += a
        else:
            mf.add_edge(i, T, -a)
    
    # Add column nodes
    for j in range(W):
        b = B[j]
        if b > 0:
            mf.add_edge(S, H + j, b)
            total_positive += b
        else:
            mf.add_edge(H + j, T, -b)
    
    # Add edge nodes for each i,j
    for i in range(H):
        for j in range(W):
            g = G[i][j]
            edge_node = edge_node_start + i * W + j
            if g > 0:
                mf.add_edge(S, edge_node, g)
                total_positive += g
            else:
                mf.add_edge(edge_node, T, -g)
            # Add edges from edge_node to row i and column j
            mf.add_edge(edge_node, i, INF)
            mf.add_edge(edge_node, H + j, INF)
    
    max_flow_val = mf.max_flow(S, T)
    result = total_positive - max_flow_val
    print(result)

if __name__ == "__main__":
    main()
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