Data commit

Task/Prime-decomposition/JavaScript/prime-decomposition-2.js

@@ -0,0 +1,40 @@
+function run_factorize(n) {
+    if (n <= 3)
+        return [n];
+
+    var ans = [];
+    var done = false;
+    while (!done) {
+        if (n % 2 === 0) {
+            ans.push(2);
+            n /= 2;
+            continue;
+        }
+        if (n % 3 === 0) {
+            ans.push(3);
+            n /= 3;
+            continue;
+        }
+        if (n === 1)
+            return ans;
+        var sr = Math.sqrt(n);
+        done = true;
+        // try to divide the checked number by all numbers till its square root.
+        for (var i = 6; i <= (sr + 6); i += 6) {
+            if (n % (i - 1) === 0) { // is n divisible by i-1?
+                ans.push((i - 1));
+                n /= (i - 1);
+                done = false;
+                break;
+            }
+            if (n % (i + 1) === 0) { // is n divisible by i+1?
+                ans.push((i + 1));
+                n /= (i + 1);
+                done = false;
+                break;
+            }
+        }
+    }
+    ans.push(n);
+    return ans;
+}