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