code: func MergeIndexMaps(map1, map2 []int) []int {
  	result := make([]int, len(map2))
  	for i, v := range map2 {
  		result[i] = map1[v]
  	}
  
  	return result
  }
docs: // MergeIndexMaps merges two index maps for use when chaining reducers.
  // For example, to radially reduce and then DP, merge the index maps with this function
  // to get a map from the original to the final path.