gistfile1.js

var Leaf = function (value) {
  this.right = null;
  this.left = null;
  this.value = value || null;
};
var Tree = function () {
  this.root = null;
};
Tree.prototype.addLeaf = function (value) {
  if (this.root === null) {
    this.root = new Leaf(value);
  } else {
    var parent = this.findParent(this.root, value);
    if (value >= parent.value) {
      parent.right = new Leaf(value);
    } else {
      parent.left = new Leaf(value);
    }
  }
};
Tree.prototype.findValue = function (tree, value) {
  if (tree === null) {
    return null;
  } else {
    if (value === tree.value) {
      return tree;
    } else if (value >= tree.value) {
      return this.findValue(tree.right, value);
    } else if (value < tree.value) {
      return this.findValue(tree.left, value);
    }
  }
};
Tree.prototype.findParent = function (tree, value) {
  if (value >= tree.value) {
    if (tree.right === null) {
      return tree;
    } else {
      return this.findParent(tree.right, value);
    }
  }
  if (value < tree.value) {
    if (tree.left === null) {
      return tree;
    } else {
      return this.findParent(tree.left, value);
    }
  }
};
var fs = require('fs');
var tree = new Tree();
fs.readFile('./source.txt', function (err, content) {
  var array = content.toString().split('\n').map(function (num) {
    return parseInt(num, 10);
  });
  array.pop(); //последний \n дает NaN
  array.forEach(function (num) {
    tree.addLeaf(num);
  });
  var lookingFor = process.argv.pop();
  console.log('looking for ' + lookingFor);
  array.forEach(function (num) {
    var part = lookingFor - num;
    if (part < 0) {
      return;
    }
    if (tree.findValue(tree.root, part)) {
      console.log('yes');
      process.exit(0);
    }
  });
  console.log('no');
});