## Get indices of elements in a list that satisfies certain sum value - python

I tried to get the indices of elements in a list, which summed of the value equal to certain number.
a = [50, 50, 50, 50, 75, 75]
b = 125
in the example above, I am looking for indices of element in list a that summed values equal to b (=125). indices combination that I am looking for is [0, 4], corresponding to the first number 50 and the first number 75.
I found a way by first creating possible combinations of the element in list a using itertools.combinations and then filter all combination that summed value equal to 125. it leads to indices [0,4], [1,4], [2,4],... This is quite problematic for list a that has many elements.
is there any simple way in python?
thank you.

Try this:
li = []
for i,j in enumerate(a):
for z,x in enumerate(a):
if int(x)+int(j) == int(b) and i>z:
li.append([i,z])

## Related

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argmin will return the index of the smallest element of the array passed; however, because this array starts at 20, you will need to add that starting point of your sublist, to obtain the index of the same smallest element in the original array: start = 20 print(np.argmin(L[start:]) + start)

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