text: /// https://leetcode.com/problems/minimum-size-subarray-sum/description/
  /// Author : liuyubobobo
  /// Time   : 2017-11-13
  
  // Sliding Window
  // Another Implementation
  // Time Complexity: O(n)
  // Space Complexity: O(1)
  public class Solution5 {
  
      public int minSubArrayLen(int s, int[] nums) {
  
          if(s <= 0 || nums == null)
              throw new IllegalArgumentException("Illigal Arguments");
  
          int l = 0 , r = -1; // sliding window: nums[l...r]
          int sum = 0;
          int res = nums.length + 1;
  
          while(r + 1 < nums.length){
  
              while(r + 1 < nums.length && sum < s)
                  sum += nums[++r];
  
              if(sum >= s)
                  res = Math.min(res, r - l + 1);
  
              while(l < nums.length && sum >= s){
                  sum -= nums[l++];
                  if(sum >= s)
                      res = Math.min(res, r - l + 1);
              }
          }
  
          return res == nums.length + 1 ? 0 : res;
      }
  
      public static void main(String[] args) {
  
          int[] nums = {2, 3, 1, 2, 4, 3};
          int s = 7;
          System.out.println((new Solution5()).minSubArrayLen(s, nums));
      }
  }
  