用尾递归(tailRecursive)实现的阶乘-JavaScript版本
<html> <script> function factorial(n){ if(n ===1) { return 1; } return n *factorial(n -1); } function tailFactorial(n, total) { if(n ===1) return total; return tailFactorial(n -1, n * total); } function factorial2(n) { return tailFactorial(n,1); } var N = 20; console.time("normal recursive"); console.log(factorial(N)); console.timeEnd("normal recursive"); console.time("tail recursive"); console.log(factorial2(N)); console.timeEnd("tail recursive"); </script> </html>
