carloscn
commented
1 year ago Analysis
pub fn build_array(nums: Vec<i32>) -> Vec<i32>
{
if nums.is_empty() {
return nums;
}
let mut ret:Vec<i32> = vec![0; nums.len()];
for i in 0..ret.len() {
let e = nums[i] as usize;
if e < nums.len() {
ret[i] = nums[e];
} else {
return vec![];
}
}
return ret;
}
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.