Code Signal_练习题_arrayMaxConsecutiveSum

Given array of integers, find the maximal possible sum of some of its k consecutive elements.

Example

For inputArray = [2, 3, 5, 1, 6] and k = 2, the output should be
arrayMaxConsecutiveSum(inputArray, k) = 8.
All possible sums of 2 consecutive elements are:

• 2 + 3 = 5;
• 3 + 5 = 8;
• 5 + 1 = 6;
• 1 + 6 = 7.
  Thus, the answer is 8.

我的解答：

第一种：
def arrayMaxConsecutiveSum(inputArray, k):
    return max([sum(inputArray[i:i + k]) for i in range(len(inputArray))])
第二种：
def arrayMaxConsecutiveSum(inputArray, k):
    return sorted([sum(inputArray[i:i + k]) for i in range(len(inputArray))])[-1]

这两种虽然都可以运行，但是运行时间太慢了.

def arrayMaxConsecutiveSum(inputArray, k):
    # return max([sum(inputArray[i:k+i]) for i in range(len(inputArray) - k + 1)])
    # too slow, but works
    s = m = sum(inputArray[:k])
    for i in range(k, len(inputArray)):
        s += inputArray[i] - inputArray[i-k]
        if s > m: m = s
    return m

膜拜大佬