i have a problem regarding the following situation. I have two arrays of numbers like this:index/pos     0   1   2   3   4   5   6   7   8   9  10  11  12  13  14  15 Array 1(i):   1   2   3   4   7   5   4   3   7   6   5   1   2   3   4   2Array 2(j):   4   4   8  10  10   7   7  10  10  11   7   4   7   7   4now suppose the second array is very hard to compute but I have noticed that if I add  A[i] + A[i+1]in the array 1 I get the number very close to the number A[j] in the array 2. Is my solution a heuristic or approximation?If I had a reason to believe that I will never overshoot the value of A[j] by +-x with this algorithm and can prove it, would then  my solution be a heuristic or approximation?Is there any literature that deals with heuristic vs. approximation questions for P class problems where the solution can be achieved in polynomial time but the input is just too big for a poly time algorithm to be practical.thank you 
Difference between heuristic and approximation algorithm?
approximation;heuristics