give array integer num integer target return index number add targetyou assume input exactly solution use element twiceyou return answer order Example 1input num 271115 target 9output 01Explanation because nums0 nums1 9 return 0 1example 2input num 324 target 6output 12example 3input num 33 target 6output 01 constraints2 numslength 104109 numsi 109109 target 109only valid answer exist Followup can come algorithm on2 time complexity