In an Array, find the Smallest Subarray with Sum Greater than the Given Value

Objective: Given an array and an integer, find the smallest subarray whose sum is greater than the given integer.

Examples:

arrA[] = { 1, 5, 20, 70, 8}
Integer = 97
Output : Min Length = 3 Subarray = [20, 70, 8]

 
arrA[] = { 1, 10, 3, 40, 18}
Integer = 50
Output : Min Length = 2 Subarray = [40, 18]

Approach:

Naive Approach: Use 2 loops . Time Complexity – O(n2).

Better Approach: Time Complexity – O(n)

  • Initialize minLength = length of the array and say the given integer is x.
  • Take variables currSum = 0, start = 0
  • Do the linear scan in array and start adding each element to the currSum.
  • if currSum > x then start subtracting element from the start.(currSum-arrA[start]) check the length of the subarray, if it is less then the minLength (currentIndex-start<minLength)update minLength and store the current index and start index for finding the subarray.

Complete Code:


Output:

Min length of subarray to get 50 is : 2
SubArray is:   40   18

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If you find anything incorrect or you feel that there is any better approach to solve the above problem, please write comment.
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