From 37e8eabc45293e4068b01072af2720f8129c47b5 Mon Sep 17 00:00:00 2001
From: Samehadar <stels95@list.ru>
Date: Mon, 25 Mar 2019 00:38:37 +0300
Subject: [PATCH] Optimize isPrime method.

---
 interactive/ec.js | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/interactive/ec.js b/interactive/ec.js
index e82d6437a96..9f3dfed94da 100644
--- a/interactive/ec.js
+++ b/interactive/ec.js
@@ -91,20 +91,24 @@
         }
     };
 
-    var isPrime = function( n ) {
+    var isPrime = function (n) {
         n = +n;
 
         if( n < 2 || n % 2 === 0 ) {
             return n === 2;
         }
 
-        for( var m = 3; m < n; m += 2 ) {
-            if( n % m === 0 ) {
-                return false;
+        let prime = n !== 1;
+        const sqrtN = Math.floor(Math.sqrt(n));
+
+        for (var m = 3; m < sqrtN + 1; m += 2) {
+            if (n % m === 0) {
+                prime = false;
+                break;
             }
         }
 
-        return true;
+        return prime;
     };
 
     ///////////////////////////////////////////////////////////////////////////