209. Minimum Size Subarray Sum
数组：滑动窗口拯救了你
Given an array of positive integers nums and a positive integer target, return the minimal length of a contiguous subarray [numsl, numsl+1, …, numsr-1, numsr] of which the sum is greater than or equal to target. If there is no such subarray, return 0 instead.
Example 1:
Input: target = 7, nums = [2,3,1,2,4,3] Output: 2 Explanation: The subarray [4,3] has the minimal length under the problem constraint.
Example 2:
Input: target = 4, nums = [1,4,4] Output: 1
Example 3:
Input: target = 11, nums = [1,1,1,1,1,1,1,1] Output: 0
Constraints:
1 <= target <= 109 1 <= nums.length <= 105 1 <= nums[i] <= 105
Follow up: If you have figured out the O(n) solution, try coding another solution of which the time complexity is O(n log(n)).
JAVA实现代码：
class Solution {
public int minSubArrayLen(int target, int[] nums) {
int sum=0;
int slowIndex=0;
int length=Integer.MAX_VALUE;
for(int fastIndex=0;fastIndex=target){
int sumLength=fastIndex-slowIndex+1;
length=sumLength 
