Given a zero-based permutation nums, build and return array ans where ans[i] = nums[nums[i]] for each 0 <= i < nums.length.
Input: A zero-based permutation array nums of length n.
Output: Array ans where ans[i] = nums[nums[i]].
Input: [0,2,1,5,3,4]
Output: [0, 1, 2, 4, 5, 3]
Explanation: ans[0]=nums[nums[0]]=nums[0]=0. ans[1]=nums[nums[1]]=nums[2]=1. ans[2]=nums[nums[2]]=nums[1]=2. ans[3]=nums[nums[3]]=nums[5]=4. ans[4]=nums[nums[4]]=nums[3]=5. ans[5]=nums[nums[5]]=nums[4]=3.Input: [5,0,1,2,3,4]
Output: [4, 5, 0, 1, 2, 3]
Explanation: ans[0]=nums[5]=4, ans[1]=nums[0]=5, ans[2]=nums[1]=0, ans[3]=nums[2]=1, ans[4]=nums[3]=2, ans[5]=nums[4]=3.Input: [0,1,2,3,4]
Output: [0,1,2,3,4]
Explanation: Identity permutation: nums[nums[i]]=i for all i.1 <= nums.length <= 10000 <= nums[i] < nums.lengthnums is a permutation.