长度最小的子数组（滑动窗口）

/**
 * @param {number} target
 * @param {number[]} nums
 * @return {number}
 */
var minSubArrayLen = function(target, nums) {
    
    
    let size = 0;
    let sum = 0
    let result = Infinity
    for(let i=0,j=0;j<nums.length;j++){
    
    
        sum+=nums[j]
        while(sum>=target){
    
    
            size = j-i+1
            result = result<size? result:size
            sum-=nums[i++]
        }
    }
    return result == Infinity ? 0:result
};