Replace Elements in an Array — LeetCode 2295 Python Solution

The problem

You are given a 0-indexed array nums that consists of n distinct positive integers. Apply m operations to this array, where in the ith operation you replace the number operations[i][0] with operations[i][1].

Example

Input

nums = [1,2,4,6], operations = [[1,3],[4,7],[6,1]]

Output

[3,2,7,1]

Explanation

We perform the following operations on nums:

Python solution

class Solution:
    def arrayChange(self, nums: List[int], operations: List[List[int]]) -> List[int]:
        d = {x: i for i, x in enumerate(nums)}
        for x, y in operations:
            nums[d[x]] = y
            d[y] = d[x]
        return nums

Complexity

Pattern: Hash Map

Trade memory for time: remember what you have seen so the second pass never happens. LeetCode 2295. Replace Elements in an Array is filed here on both counts: the reference solution below belongs to the algorithm family this hub collects, and LeetCode tags it Hash Table.

The hash map guide has the Python template for the pattern and the 709 LeetCode problems that use it.

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