1640.CheckArraFormationThroughConcatenation.py

"""
    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 pieces in any order. However, you 
    are not allowed to reorder the integers in each array pieces[i].

    Return true if it is possible to form the array arr from pieces. 
    Otherwise, return false.

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

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

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

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

    Example:
    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).
"""
#Difficulty: Easy
#82 / 82 test cases passed.
#Runtime: 40 ms
#Memory Usage: 14 MB

#Runtime: 40 ms, faster than 86.23% of Python3 online submissions for Check Array Formation Through Concatenation.
#Memory Usage: 14 MB, less than 100.00% of Python3 online submissions for Check Array Formation Through Concatenation.

class Solution:
    def canFormArray(self, arr: List[int], pieces: List[List[int]]) -> bool:
        array = [None] * len(arr)
        for piece in pieces:
            lenght = len(piece)
            if piece[0] in arr:
                i = arr.index(piece[0])
                if arr[i:i+lenght] == piece:
                    for p in piece:
                        array[i] = p
                        i += 1
        return None not in array