Find maximum circumference of a triangles. An exercise of js

FindTriangle.js

// Triangle.js
// 
// Pick up 3 side numbers a[i] to make a triangle from n numbers. 
// Find the maximum circumference of triangles.
//
// Constraints : 
//    3 <= n <= 100
//    1 <= a[i] <= 10^6

var TRI = {};

TRI.solve = function (n, a) {
    var ans = 0;

    // i < j < k to prevent to pick same number

    for (var i = 0; i < n; i++) {
        for (var j = i + 1; j < n; j++) {
            for (var k = j + 1; k < n; k++) {
                var len = a[i] + a[j] + a[k];
                var longest = Math.max(a[i], a[j], a[k]);
                var rest = len - longest;

                //  longest side a < b + c must be a triangle.

                if (longest < rest) { 
                    ans = Math.max(ans, len);
                }
            }
        }
    }
    return ans;
};

// Test 1 : n = 5, a = {2, 3, 4, 5, 10}, answer = 12
// Test 2 : n = 4, a = {4, 5, 10, 20}, answer = 0