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ryancole/factorial.js

Created September 25, 2014 03:36
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  1. ryancole created this gist Sep 25, 2014.
    25 changes: 25 additions & 0 deletions factorial.js
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,25 @@

    function factorial (n) {
    return n <= 1 ? 1 : n * factorial(n - 1);
    };

    var factorial_memo = (function () {
    var memo = [1];
    function fac (n) {
    var result = memo[n];
    if (typeof result !== 'number') {
    result = n * fac(n - 1);
    memo[n] = result;
    }
    return result;
    };
    return fac;
    }());

    for (var i = 0; i <= 40; i += 1) {
    console.log('// ' + i + ': ' + factorial(i));
    }

    for (var i = 0; i <= 40; i += 1) {
    console.log('// ' + i + ': ' + factorial_memo(i));
    }