1042. Flower Planting With No Adjacent

You have n gardens, labeled from 1 to n, and an array paths where paths[i] = [xi, yi] describes a bidirectional path between garden xi to garden yi. In each garden, you want to plant one of 4 types of flowers.

All gardens have at most 3 paths coming into or leaving it.

Your task is to choose a flower type for each garden such that, for any two gardens connected by a path, they have different types of flowers.

Return any such a choice as an array _answer _, whereanswer[i] is the type of flower planted in the(i+1)th garden. The flower types are denoted1 ,2 ,3 , or4 . It is guaranteed an answer exists.

Example 1:

Input: n = 3, paths = [[1,2],[2,3],[3,1]]
Output: [1,2,3]
Explanation:
Gardens 1 and 2 have different types.
Gardens 2 and 3 have different types.
Gardens 3 and 1 have different types.
Hence, [1,2,3] is a valid answer. Other valid answers include [1,2,4], [1,4,2], and [3,2,1].

Example 2:

Input: n = 4, paths = [[1,2],[3,4]]
Output: [1,2,1,2]

Example 3:

Input: n = 4, paths = [[1,2],[2,3],[3,4],[4,1],[1,3],[2,4]]
Output: [1,2,3,4]

Constraints:

• 1 <= n <= 104
• 0 <= paths.length <= 2 * 104
• paths[i].length == 2
• 1 <= xi, yi <= n
• xi != yi
• Every garden has at most 3 paths coming into or leaving it.

# @lc code=start
using LeetCode

function garden_no_adj(n::Int, path::Vector{Vector{Int}})
    G = Dict{Int,Set{Int}}()
    for (u, v) in path
        push!(get!(G, u, Set{Int}()), v)
        push!(get!(G, v, Set{Int}()), u)
    end
    res = zeros(Int, n)
    for i in 1:n
        res[i] = first(setdiff(1:4, [res[j] for j in G[i]]))
    end
    return res
end

# @lc code=end

garden_no_adj (generic function with 1 method)

This page was generated using DemoCards.jl and Literate.jl.