https://leetcode.com/problems/build-array-from-permutation/ We need to loop through the nums array and fill in a new array in the proper order. func buildArray(nums []int) []int { // Create a new array of the same size as nums ans := make([]int, len(nums)) // Loop through nums for index, _ := range nums { // Fill in the new array with the proper value from nums, // taken from the question ans[index] = nums[nums[index]] } return ans}