list_2 = [2,3,4,7,8,10,0] def two_sum(list, target): d = {} for i in range(len(list)-1): for j in range(i+1,len(list)): if (list[i] + list[j]) == target: d[i] = j return d two_sum(list_2,10)

Dear Aziz, Thank you for your question! Your solution is great! Here are some suggestion I could give. The first one concerns the name you have given to the first parameter in the two_sums() function. The word list is a special word in Python - notice how it's colored differently than the rest of the text. Therefore, calling your parameter in such a way is not a good practice. Any other name would do - Giles has, for example, called this parameter nums which doesn't mean anything in Python. Next, examine how the range() function behaves (in the code below, I have used your variable list_2): On the first row, I have displayed the index i, while on the second row the index j. Notice that, in your solution, you don't take into account the case where a number, added with itself, gives the target number. For example, changing list_2 to [5, 3, 4, 7, 8, 10, 0] (I have changed the 2 at the beginning to a 5) won't give 0:0 as a possible solution. I would therefore change the second for-loop to: for j in range(i,len(nums)): Following the same logic, if we have list_2 being of the form [2, 3, 4, 7, 8, 10, 5] (I have changed the 0 at the end to a 5), we won't have 6:6 as a possible solution. I would therefore change the first for-loop as follows: for i in range(len(nums)): To sum up, the code that I suggest is the following: def two_sum(nums, target): d = {} for i in range(len(nums)): for j in range(i,len(nums)): if (nums[i] + nums[j]) == target: d[i] = j print(d) return d I have also added a line of code that prints out the dictionary every time a new element is added to it. In this way, you can track the progress and examine the behavior of the code. Hope this answer helps! Keep up the good work! Kind regards, 365 Hristina

def two_sum(nums, target): d={} count = 0 for i in range(len(nums)): for j in range(i,len(nums)): if nums[i] + nums[j] == target: count=count + 1 d={nums[i], nums[j]} print(d) if count != 0 : return 'two sums exists' else : return('two-sums does Not exist')