Build Array from Permutation

Leetcode Problem:

• Build Array from Permutation

Summary

• Given a zero-based permutation, build an array where ans[i] = nums[nums[i]] for each 0 <= i < nums.length and return it.

Approach

• This solution uses a simple iterative approach where it iterates over the input array and uses the value at each index as the index for the next value in the output array.

Complexity

• O(n) where n is the length of the input array

Explanation

• The solution uses a vector to store the output array and iterates over the input array
• For each index in the input array, it uses the value at that index as the index for the next value in the output array
• This approach is simple and efficient, with a time complexity of O(n) where n is the length of the input array.

Solution Code:

class Solution {
public:
    vector ans;
    vector buildArray(vector& nums) {
        for(int i = 0 ; i < nums.size(); i++){
            ans.push_back(nums[nums[i]]);
        }
        return ans;
    }
};