Minimum Size Subarray Sum Solution

Question

Given an array of n positive integers and a positive integer s, find the minimal length of a subarray of which the Sum≥s . If there isn ' t one, return 0 instead.

For example, given the array [2,3,1,2,4,3] and s = 7 ,
The subarray has the [4,3] minimal length under the problem constraint.

Solution 1--pointers

Following the thought of Slide window, we apply the pointers here to solve the problem, one for left and one for right.

If current sum >= target, left++;

If current sum < target, right--;

Remember to check the right index before getting nums[right], and sum value are nums[0] at beginning.

Time complexity O (n).

1  Public classSolution {2      Public intMinsubarraylen (intSint[] nums) {3         if(Nums = =NULL|| Nums.length = = 0)4             return0;5         intLength = nums.length, left = 0, right = 0, result = length, sum = nums[0];6          while(Right <length) {7             if(left = =Right ) {8                 if(Nums[left] >=s) {9                     return1;Ten}Else { Oneright++; A                     if(Right <length) -Sum + =Nums[right]; -                     Else the                          Break; -                 } -}Else { -                 if(Sum <s) { +right++; -                     if(Right <length) +Sum + =Nums[right]; A                     Else at                          Break; -}Else { -result = Math.min (result, Right-left + 1); -Sum-=Nums[left]; -left++; -                 } in             } -         } to         if(left = = 0 && sum <s) +result = 0; -         returnresult; the     } *}

Minimum Size Subarray Sum Solution