Reason for NO TLE in C

This is because there are total n*(n-1)/2 pairs of two numbers possible. So there can be maximum n*(n-1)/2 different sums possible.

And from the constraint a[i]<=2.5*10^6. So, maximum possible sum will be 5*10^6.

That's why when n*(n-1)/2 is greater than 5*10^6, then answer always exists. So, when n>4000, the there always exist a answer. Hence not getting TLE.

Also same codes are getting accepted after contest which got TLE during the contest

Agar koi alternative apps ho, toh please bata dena