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Copy pathmain.rb
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58 lines (46 loc) · 1.19 KB
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N, M = gets.chomp.split.map(&:to_i)
INF = 10**25
D = Array.new(N + 1) { Array.new(N + 1, INF) }
T = Array.new(N + 1) { Array.new(N + 1, 0) }
M.times do
s, t, d, time = gets.chomp.split.map(&:to_i)
s -= 1
t -= 1
D[s][t] = d
D[t][s] = d
T[s][t] = time
T[t][s] = time
end
# 最短時間、組み合わせ
dp = Array.new(1 << N) { Array.new(N + 1) { [INF, 0] } }
# フラグが立っていない時に最後にいるのは1
# 最初にいるばしょ
dp[0][0] = [0, 1]
1.upto((1 << N) - 1) do |s|
# i: 最後にいる場所
N.times do |i|
# 最後にいる場所が集合に含まれていなかったらスキップ
next if 1 & (s >> i) != 1
arr = []
N.times do |j|
# 間に合わない場合
# 最後にいる都市: 都市 i
time = dp[s & ~(1 << i)][j][0] + D[j][i]
next if T[j][i] < time
com = dp[s & ~(1 << i)][j][1]
arr << [time, com]
end
next if arr.empty?
min_time = arr.min_by { |v| v[0] }[0]
dp[s][i][0] = min_time
arr.each do |t, com|
next unless t == min_time
dp[s][i][1] += com
end
end
end
if dp[(1 << N) - 1][0][0] >= INF
puts 'IMPOSSIBLE'
else
puts dp[(1 << N) - 1][0] * ' '
end