Cycle Detection: Floyd's The Tortoise and the The Hare

2019-11-23 23:43:02 +01:00
parent 42949295cb
commit 06f01d2ef9
1 changed files with 15 additions and 0 deletions
--- a/cycle-detection-floyds-the-tortoise-and-the-the-hare/index.js
+++ b/cycle-detection-floyds-the-tortoise-and-the-the-hare/index.js
@@ -0,0 +1,15 @@
+// https://www.codewars.com/kata/cycle-detection-floyds-the-tortoise-and-the-the-hare/javascript
+
+const floyd = function(f, x0) {
+  let x = x0;
+  let i = 0;
+  const map = new WeakMap();
+  
+  while (1) {
+    map[x] = i++;
+    x = f(x);
+    if (x in map) break;
+  }
+  
+  return  [map[x], i - map[x]];
+}