1920. Build Array from Permutation
Description
Given a zero-based permutation nums
(0-indexed), build an array ans
of the same length where ans[i] = nums[nums[i]]
for each 0 <= i < nums.length
and return it.
A zero-based permutation nums
is an array of distinct integers from 0
to nums.length - 1
(inclusive).
Example 1:
Input: nums = [0,2,1,5,3,4] Output: [0,1,2,4,5,3] Explanation: The array ans is built as follows: ans = [nums[nums[0]], nums[nums[1]], nums[nums[2]], nums[nums[3]], nums[nums[4]], nums[nums[5]]] = [nums[0], nums[2], nums[1], nums[5], nums[3], nums[4]] = [0,1,2,4,5,3]
Example 2:
Input: nums = [5,0,1,2,3,4] Output: [4,5,0,1,2,3] Explanation: The array ans is built as follows: ans = [nums[nums[0]], nums[nums[1]], nums[nums[2]], nums[nums[3]], nums[nums[4]], nums[nums[5]]] = [nums[5], nums[0], nums[1], nums[2], nums[3], nums[4]] = [4,5,0,1,2,3]
Constraints:
1 <= nums.length <= 1000
0 <= nums[i] < nums.length
- The elements in
nums
are distinct.
Follow-up: Can you solve it without using an extra space (i.e., O(1)
memory)?
Solutions
Solution 1
1 2 3 |
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1 2 3 4 5 6 7 8 9 |
|
1 2 3 4 5 6 7 8 9 10 |
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1 2 3 4 5 6 7 |
|
1 2 3 |
|
1 2 3 4 5 |
|
1 2 3 4 5 6 7 8 9 10 11 |
|
1 2 3 4 5 6 7 8 9 10 11 |
|