Smallest subarray with sum greater than x.cpp

/*
Smallest subarray with sum greater than x
==========================================

Given an array of integers (A[])  and a number x, find the smallest subarray with sum greater than the given value.

Note: The answer always exists. It is guaranteed that x doesn't exceed the summation of a[i] (from 1 to N).

Example 1:
Input:
A[] = {1, 4, 45, 6, 0, 19}
x  =  51
Output: 3
Explanation:
Minimum length subarray is 
{4, 45, 6}

Example 2:
Input:
A[] = {1, 10, 5, 2, 7}
  x  = 9
Output: 1
Explanation:
Minimum length subarray is {10}

Your Task:  
You don't need to read input or print anything. Your task is to complete the function sb() which takes the array A[], its size N and an integer X as inputs and returns the required ouput.

Expected Time Complexity: O(N)
Expected Auxiliary Space: O(1)

Constraints:
1 ≤ N, x ≤ 105
1 ≤ A[] ≤ 104
*/

int sb(int arr[], int n, int x)
{
  int curr_sum = 0, min_len = n + 1;
  int start = 0, end = 0;

  while (end < n)
  {
    while (curr_sum <= x && end < n)
    {
      curr_sum += arr[end];
      end++;
    }

    while (curr_sum > x && start < n)
    {
      min_len = min(min_len, end - start);
      curr_sum -= arr[start];
      start++;
    }
  }
  return min_len;
}