力扣209.长度最小的数组

力扣209.长度最小的数组

• 模版滑窗求最小

•   class Solution {
    public:
        int minSubArrayLen(int target, vector<int>& nums) {
            int n = nums.size(),res=n+1;
            int sum = 0;
            for(int i=0,j=0;i<n;i++)
            {
                sum += nums[i];
                //尽可能缩小区间
                while(sum - nums[j] >= target)
                {
                    sum -= nums[j++];
                }
                if(sum >= target) res = min(res,i-j+1);
            }
            if(res == n+1) return 0;
            else return res;
        }
    };