Determine whether a triangle can be built from a given set of edges.
An array A consisting of N integers is given. A triplet (P, Q, R) is triangular if 0 ≤ P < Q < R < N and:

• A[P] + A[Q] > A[R],
• A[Q] + A[R] > A[P],
• A[R] + A[P] > A[Q].

For example, consider array A such that:

A[0] = 10 
A[1] = 2 
A[2] = 5 
A[3] = 1 
A[4] = 8 
A[5] = 20

Triplet (0, 2, 4) is triangular.

Write an efficient algorithm for the following assumptions:

• $N$ is an integer within the range $[0..100,000]$;
• each element of array $A$ is an integer within the range $[−2,147,483,648..2,147,483,647]$.

returns 1 if there exists a triangular triplet for this array and returns 0 otherwise.