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1640. Check Array Formation Through Concatenation

You are given an array of distinct integers arr and an array of integer arrays pieces, where the integers in pieces are distinct. Your goal is to form arr by concatenating the arrays in piecesin any order. However, you are not allowed to reorder the integers in each array pieces[i].

Return trueif it is possible to form the arrayarrfrompieces. Otherwise, return false.

Example 1:

Input: arr = [85], pieces = [[85]] Output: true 

Example 2:

Input: arr = [15,88], pieces = [[88],[15]] Output: true Explanation: Concatenate [15] then [88] 

Example 3:

Input: arr = [49,18,16], pieces = [[16,18,49]] Output: false Explanation: Even though the numbers match, we cannot reorder pieces[0]. 

Example 4:

Input: arr = [91,4,64,78], pieces = [[78],[4,64],[91]] Output: true Explanation: Concatenate [91] then [4,64] then [78] 

Example 5:

Input: arr = [1,3,5,7], pieces = [[2,4,6,8]] Output: false 

Constraints:

• 1 <= pieces.length <= arr.length <= 100
• sum(pieces[i].length) == arr.length
• 1 <= pieces[i].length <= arr.length
• 1 <= arr[i], pieces[i][j] <= 100
• The integers in arr are distinct.
• The integers in pieces are distinct (i.e., If we flatten pieces in a 1D array, all the integers in this array are distinct).

Solutions (Ruby)

1. Sort

# @param {Integer[]} arr# @param {Integer[][]} pieces# @return {Boolean}defcan_form_array(arr,pieces)indices=arr.map.with_index.to_hindices.default=0arr == pieces.sort_by{ |piece| indices[piece[0]]}.flatten(1)end

Solutions (Rust)

1. Sort

use std::collections::HashMap;implSolution{pubfncan_form_array(arr:Vec<i32>,mutpieces:Vec<Vec<i32>>) -> bool{let indices = arr .iter().enumerate().map(|(i, n)| (n, i)).collect::<HashMap<_,_>>(); pieces.sort_unstable_by_key(|piece| indices.get(&piece[0])); arr == pieces.concat()}}