1640. Check Array Formation Through Concatenation

class Solution:
    def canFormArray(self, arr: List[int], pieces: List[List[int]]) -> bool:
        d = {p[0]: p for p in pieces}
        i, n = 0, len(arr)
        while i < n:
            if arr[i] not in d:
                return False
            p = d[arr[i]]
            if arr[i : i + len(p)] != p:
                return False
            i += len(p)
        return True