Sums_of_Parts.md

CodeWars Python Solutions

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Sums of Parts

Let us consider this example (array written in general format):

ls = [0, 1, 3, 6, 10]

Its following parts:

ls = [0, 1, 3, 6, 10]
ls = [1, 3, 6, 10]
ls = [3, 6, 10]
ls = [6, 10]
ls = [10]
ls = []

The corresponding sums are (put together in a list): [20, 20, 19, 16, 10, 0]

The function parts_sums (or its variants in other languages) will take as parameter a list ls and return a list of the sums of its parts as defined above.

Other Examples:

ls = [1, 2, 3, 4, 5, 6]
parts_sums(ls) -> [21, 20, 18, 15, 11, 6, 0]

ls = [744125, 935, 407, 454, 430, 90, 144, 6710213, 889, 810, 2579358]
parts_sums(ls) -> [10037855, 9293730, 9292795, 9292388, 9291934, 9291504, 9291414, 9291270, 2581057, 2580168, 2579358, 0]

Notes

• Some lists can be long.
• Please ask before translating: some translations are already written and published when/if the kata is approved.

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Given Code

def parts_sums(ls):
    pass

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Solution 1

def parts_sums(ls):
    cop = list(ls)
    top = sum(ls)
    sums = 0
    parts = []
    for i in range(len(ls)):
        if len(parts) == 0:
            parts.append(top)
        else:
            parts.append(top - sums)
        sums += cop[i]
    parts.append(0)
    return parts

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Solution 2

def parts_sums(ls):
    sums = [sum(ls)]
    for i in ls:
        sums.append(sums[-1]-i)
    return sums

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