code.delx.au - gnu-emacs-elpa/blob - packages/realgud/test/node_modules/gcd.js/gcd.js

   1 //!/usr/bin/env node
   2 var util = require("util");
   3 require("console");
   4
   5 function ask(question, format, callback) {
   6  var stdin = process.stdin, stdout = process.stdout;
   7
   8  stdin.resume();
   9  stdout.write(question + ": ");
  10
  11  stdin.once('data', function(data) {
  12    data = data.toString().trim();
  13
  14    if (format.test(data)) {
  15      callback(data);
  16    } else {
  17      stdout.write("It should match: "+ format +"\n");
  18      ask(question, format, callback);
  19    }
  20  });
  21 }
  22
  23 // GCD. We assume positive numbers
  24 function gcd(a, b) {
  25     // Make: a <= b
  26     if (a > b) {
  27         var temp = a;
  28         a = b;
  29         b = temp;
  30     }
  31
  32     if (a <= 0) { return null };
  33
  34     if (a == 1 || b-a == 0) {
  35         return a;
  36     }
  37     return gcd(b-a, a);
  38 }
  39
  40 var a=24;
  41
  42 ask("GCD of 24 and", /^\d+$/, function(b_str) {
  43     var b = parseInt(b_str, 10);
  44     console.log(util.format("The GCD of %d and %d is %d", a, b,
  45                             gcd(a, b)));
  46     process.exit();
  47 });