add Triangle

Author: talgat-ruby

README.md

@@ -28,6 +28,7 @@
     -   [Lesson 6 - Sorting](#s_6)
         -   [MaxProductOfThree](#s_6_max_product_of_three)
         -   [Distinct](#s_6_distinct)
+        -   [Triangle](#s_6_triangle)
 -   [Licence](#licence)
 
 <a name="installation"></a>
@@ -270,6 +271,18 @@ https://github.com/talgat-ruby/codility-lessons-javascript/blob/master/lesson6_s
 
 https://app.codility.com/demo/results/trainingBVMXV7-F9S/
 
+<a name="s_6_triangle"></a>
+
+#### Triangle
+
+##### File
+
+https://github.com/talgat-ruby/codility-lessons-javascript/blob/master/lesson6_sorting/Triangle.js
+
+##### Link to Report
+
+https://app.codility.com/demo/results/training62TT8U-DCH/
+
 <a name="licence"></a>
 
 ## License

lesson6_sorting/Triangle.js

@@ -0,0 +1,14 @@
+function solution(A) {
+    const len = A.length;
+    if (len >= 3) {
+        A.sort((a, b) => a - b);
+        for (let i = 2; i < len; i++) {
+            if (A[i - 2] + A[i - 1] > A[i]) {
+                return 1;
+            }
+        }
+    }
+    return 0;
+}
+
+module.exports = solution;

lesson6_sorting/Triangle.test.js

@@ -0,0 +1,13 @@
+const solution = require("./Triangle");
+
+describe("test Triangle", () => {
+    test("[10, 2, 5, 1, 8, 20] -> 1", () => {
+        expect(solution([10, 2, 5, 1, 8, 20])).toBe(1);
+    });
+    test("[10, 50, 5, 1] -> 0", () => {
+        expect(solution([10, 50, 5, 1])).toBe(0);
+    });
+    test("[1, 1, 1, 1, 5, 5, 5] -> 1", () => {
+        expect(solution([1, 1, 1, 1, 5, 5, 5])).toBe(1);
+    });
+});