Given an array that contains positive integers. The task is to calculate the number of triplets a, b, c such that they can be the sides of a triangle or
max(a, b, c) < a + b + c - max(a, b, c)
the O(N^3) solution is trivial using 3 loops, O(N^2) is simple enough to iterate over from the end of the sorted array and find a valid range satisfying the triangle inequality. But is it possible to find the count from a sorted array in linear time by iterating and fixing the middle length?