5)Longest Sub-Array with Sum K -(sliding window |variable size)

Given an array containing N integers and an integer K., Your task is to find the length of the longest Sub-Array with the sum of the elements equal to the given value K.

 

Example 1:
 

Input :
A[] = {10, 5, 2, 7, 1, 9}
K = 15
Output : 4
Explanation:
The sub-array is {5, 2, 7, 1}.

method:

sliding window ,works only for positive numbers.

c++ implementation:

 int lenOfLongSubarr(int a[],  int n, int k) 
    {
        int i=0;int j=0;
        int s=0;int len=0;
        
        while(j<n)
        {
            s=s+a[j];
        
            if(s==k)
            {
                len=max(len,j-i+1);
            }
            else if(s>k)
            {
                while(s>k)
                {
                    s=s-a[i];
                    i++;
                }
                if(s==k)
                {
                len=max(len,j-i+1);
                } 
                
            }
            j++;
        }
        return len;
    }

Time Complexity: O(n) 

space Complexity: O(1)