209. Minimum Size Subarray Sum

 1     public int minSubArrayLen(int s, int[] nums) {
 2         if(nums.length == 0) {
 3             return 0;
 4         }
 5         int walker = 0;
 6         int runner = 0;
 7         int curSum = 0;
 8         int minLen = Integer.MAX_VALUE;
 9         while(runner < nums.length) {
10             curSum += nums[runner];
11             runner++;
12             while(curSum - nums[walker] >= s) {
13                 curSum -= nums[walker];
14                 walker++;
15             }
16             if(curSum >= s) {
17                 minLen = Math.min(minLen, runner - walker);
18             }
19         }
20         return minLen == Integer.MAX_VALUE? 0: minLen;
21     }