643.Maximum Average Subarray I

643.Maximum Average Subarray I

难度:Easy Given an array consisting of n integers, find the contiguous subarray of given length k that has the maximum average value. And you need to output the maximum average value.

Example 1:

Input: [1,12,-5,-6,50,3], k = 4
Output: 12.75
Explanation: Maximum average is (12-5-6+50)/4 = 51/4 = 12.75
 

Note:

1 <= k <= n <= 30,000.
Elements of the given array will be in the range [-10,000, 10,000].

窗口滑动，遍历一遍。

class Solution {
public:
    double findMaxAverage(vector<int>& nums, int k) {
        int sum=accumulate(nums.begin(),nums.begin()+k,0);
        int maxSum=sum;
        for(int i=k;i<nums.size();i++)
        {
            maxSum=max(maxSum, sum+=nums[i]-nums[i-k]);
        }
        return maxSum/double(k);
    }
};

执行用时 :164 ms, 在所有 C++ 提交中击败了94.19%的用户 内存消耗 :16.8 MB, 在所有 C++ 提交中击败了68.97%的用户