Implement a program to find the common elements in two arrays without using any extra data structures.

Sure , I ' ll do my best to assist you with care , respect , and truth . To find the common elements in two arrays without using any extra data structures , we can use a hash table . Here ' s an example implementation in Python : \n `` ` python def common _ elements ( arr 1 , arr 2 ): \n # Create a hash table to store the elements of the first array \n hash _ table = {} \n for element in arr 1 : \n if element in hash _ table : \n hash _ table [ element ]. append ( element ) \n else : \n hash _ table [ element ] = [ element ] \n \n # Check if any elements in the second array are in the hash table \n for element in arr 2 : \n if element in hash _ table : \n return hash _ table [ element ] \n return [] \n `` ` \n This implementation has a time complexity of O ( n ) and a space complexity of O ( n ), where n is the length of the arrays . </s>