Simple one

Let there be n integers in ascending order.design an O(n) algorithm such that this algorithm finds two integers from this list that adds upto zero otherwise it will say that there is no such pair of integers.

*take two integers assign fist index of array to one integer say i & assign last index to another integer say j
* take the sum of values at these position sum=a[i]+a[j]
while(i<=j)
******if(sum<0)
******* then move forward means increment in i
******if(sum>0)
******* then move backward mean decrement in j
****** if(sum==0)
******* return i,j
*return false