Leetcode 2295. Replace Elements in an Array

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].

It is guaranteed that in the ith operation:

• operations[i][0] exists in nums.

• operations[i][1] does not exist in nums.

Return the array obtained after applying all the operations.

Example 1:

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: 

- Replace the number 1 with 3. nums becomes [3,2,4,6]. 

- Replace the number 4 with 7. nums becomes [3,2,7,6]. 

- Replace the number 6 with 1. nums becomes [3,2,7,1]. 

We return the final array [3,2,7,1].

Example 2:

Input: nums = [1,2], operations = [[1,3],[2,1],[3,2]]

Output: [2,1]

Explanation: We perform the following operations to nums:

- Replace the number 1 with 3. nums becomes [3,2].

- Replace the number 2 with 1. nums becomes [3,1].

- Replace the number 3 with 2. nums becomes [2,1].

We return the array [2,1].

Constraints:

• n == nums.length

• m == operations.length

• 1 <= n, m <= 105

• All the values of nums are distinct.

• operations[i].length == 2

• 1 <= nums[i], operations[i][0], operations[i][1] <= 106

• operations[i][0] will exist in nums when applying the ith operation.

• operations[i][1] will not exist in nums when applying the ith operation.

以为用map会稍微快一点，结果。。。

Runtime: 68 ms, faster than 19.71% of Java online submissions for Replace Elements in an Array.

Memory Usage: 92.9 MB, less than 71.14% of Java online submissions for Replace Elements in an Array.