Determine whether a triangle can be built from a given set of edges.

Task description: 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 = 10 A = 2 A = 5 A = 1 A = 8 A = 20

Triplet (0, 2, 4) is triangular.

Write a function:

function solution(A);

that, given an array A consisting of N integers, returns 1 if there exists a triangular triplet for this array and returns 0 otherwise.

For example, given array A such that: A = 10 A = 2 A = 5 A = 1 A = 8 A = 20

the function should return 1, as explained above. Given array A such that: A = 10 A = 50 A = 5 A = 1

the function should return 0.

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].
function solution(A) {
// write your code in JavaScript (Node.js 4.0.0)

if(A.length < 3) {
return 0;
}

A.sort(function(a, b) {
return a-b;
});

for(var i=2; i<A.length; i++) {
if(validate(A[i-2], A[i-1], A[i])) {
return 1;
}
}

return 0;
}

function validate(val0, val1, val2) {
var result = true;

result = result && (val0 + val1 > val2);
result = result && (val0 + val2 > val1);
result = result && (val1 + val2 > val0);

return result;
}

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