题目如下:
Given an array
A
of non-negative integers, return the maximum sum of elements in two non-overlapping (contiguous) subarrays, which have lengthsL
andM
. (For clarification, theL
-length subarray could occur before or after theM
-length subarray.)Formally, return the largest
V
for whichV = (A[i] + A[i+1] + ... + A[i+L-1]) + (A[j] + A[j+1] + ... + A[j+M-1])
and either:
0 <= i < i + L - 1 < j < j + M - 1 < A.length
, or0 <= j < j + M - 1 < i < i + L - 1 < A.length
.
Example 1:
Input: A = [0,6,5,2,2,5,1,9,4], L = 1, M = 2 Output: 20 Explanation: One choice of subarrays is [9] with length 1, and [6,5] with length 2.
Example 2:
Input: A = [3,8,1,3,2,1,8,9,0], L = 3, M = 2 Output: 29 Explanation: One choice of subarrays is [3,8,1] with length 3, and [8,9] with length 2.
Example 3:
Input: A = [2,1,5,6,0,9,5,0,3,8], L = 4, M = 3 Output: 31 Explanation: One choice of subarrays is [5,6,0,9] with length 4, and [3,8] with length 3.
Note:
L >= 1
M >= 1
L + M <= A.length <= 1000
0 <= A[i] <= 1000
解题思路:A的长度最大只有1000,表示O(n^2)的复杂度可以接受,那么直接用嵌套的两个循环暴力计算吧。
代码如下:
class Solution(object): def maxSumTwoNoOverlap(self, A, L, M): """ :type A: List[int] :type L: int :type M: int :rtype: int """ val = [] count = 0 for i in range(len(A)): count += A[i] val.append(count) res = 0 for i in range(len(A)-L+1): for j in range(len(A)-M+1): if i == 0 and j == 2: pass if (j+M-1) < i or (i+L-1) < j: v2 = val[j+M-1] if j>=1: v2 -= val[j-1] v1 = val[i+L-1] if i >= 1: v1 -= val[i - 1] res = max(res, v1 + v2) return res
【leetcode】1031. Maximum Sum of Two Non-Overlapping Subarrays