Two Pointer Approach

public class TwoPointer {
    public static void main(String[] args) {
        int array [] =  {6,7,8,9,12,13,14,15};
        int k = 27;

        // Brute force approach
        for(int i=0;i<array.length;i++) {
            for(int j= i+1;j<array.length-1;j++) {
                if(array[i]+array[j] == k) {
                    System.out.println("indices found"+ i +j);
                }
            }
        }

        // Two pointer approach optimize way time complexity 0(n)
        int start=0;
        int end= array.length-1;
        while(start<=end) {
            if(start==end) {
                System.out.println("Not Found"); 
                break;
            }
            if(array[start]+array[end]>k) {
                end--;
            } else if(array[start]+array[end]<k) {
                start++;
            } else {
                // sum mil jaye 
                System.out.println("we found the indices "+ start+ "," + end);
                break;
            }
        }
   // Break example
    //    int k1=100;
    //     while(k>0) {
    //         if(k1==99) {
    //             break;
    //         }
    //         System.out.println(k1);
    //         k1--;
    //     }

    }
}