add problem 27

sejoker · Dec 3, 2015 · 2515668 · 2515668
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diff --git a/problems/27-stock-ticker.js b/problems/27-stock-ticker.js
@@ -0,0 +1,106 @@
+exports.problem = function () { /*
+Exercise 27: Stock Ticker
+
+Let's try an easier question. Let's say we have a collection of all of the prices for NASDAQ
+stocks over time. Every time the price of a stock changes on the NASDAQ ticker an entry is
+added to this collection. Let's say that ten days ago you bought shares in Microsoft, and now
+you want to print all of the MSFT share prices since then. Filter the collection for MSFT
+trades starting from ten days ago and print each price record (including the time stamp)
+using the print() function. Note: this is not a trick question. It's as easy as it seems. 
+
+// The pricesNASDAQ collection looks something like this...
+// var pricesNASDAQ = [
+//   ... from the NASDAQ's opening day
+//   {name: "ANGI", price: 31.22, timeStamp: new Date(2011,11,15) },
+//   {name: "MSFT", price: 32.32, timeStamp: new Date(2011,11,15) },
+//   {name: "GOOG", price: 150.43, timeStamp: new Date(2011,11,15)},
+//   {name: "ANGI", price: 28.44, timeStamp: new Date(2011,11,16)},
+//   {name: "GOOG", price: 199.33, timeStamp: new Date(2011,11,16)},
+//   ...and up to the present.
+// ];
+
+
+module.exports = function (pricesNASDAQ, printRecord) {
+  var microsoftPrices,
+    now = new Date(),
+    tenDaysAgo = new Date( now.getFullYear(), now.getMonth(), now.getDate() - 10);
+
+  // use filter() to filter the trades for MSFT prices recorded any time after 10 days ago
+  microsoftPrices =
+    pricesNASDAQ.
+      filter(function (priceRecord) {   // finish this expression
+
+  // Print the trades to the output console
+  microsoftPrices.
+    forEach(function (priceRecord) {
+      printRecord(priceRecord);
+    });
+}
+    
+*/}.toString().split('\n').slice(1, -1).join('\n')
+
+exports.solution = function () { /*
+module.exports = function (pricesNASDAQ, printRecord) {
+  var microsoftPrices,
+    now = new Date(),
+    tenDaysAgo = new Date( now.getFullYear(), now.getMonth(), now.getDate() - 10);
+
+  // use filter() to filter the trades for MSFT prices recorded any time after 10 days ago
+  microsoftPrices =
+    pricesNASDAQ.
+      filter(function (priceRecord) {
+        return priceRecord.name === 'MSFT' && priceRecord.timeStamp > tenDaysAgo;
+      });
+
+  // Print the trades to the output console
+  microsoftPrices.
+    forEach(function (priceRecord) {
+      printRecord(priceRecord);
+    });
+}
+*/}.toString().split('\n').slice(1, -1).join('\n')
+
+var verify = require('adventure-verify')
+var path = require('path')
+var Rx = require('rx');
+
+var stockSymbols = ["MSFT", "GOOG","NFLX","OSTK"],
+    input = [{name: "MSFT", price: 32.32, timeStamp: new Date() }, {name: "GOOG", price: 150.43, timeStamp: new Date(2011,11,15)}]
+
+exports.verify = verify({ modeReset: true }, function (args, t) {
+  //t.plan(4);
+  t.equal(args.length, 1, 'learnrx verify YOURFILE.js')
+  var f = require(path.resolve(args[0]))
+  t.equal(typeof f, 'function', 'you exported a function')
+
+  var expected = [input[0]],
+    counter = 0,
+    items = [],
+    confirmPrint = function (item) {
+      items.push(item);
+    },
+    print = function(item) {
+      var res = "MSFT " + item.price + " at " + item.timeStamp.toString();
+      t.ok(true)
+      counter++;
+      if (counter <= 3) {
+        console.log(res)
+      } else {
+        t.ok(true)
+      }
+    },
+    stocks =
+      Rx.Observable.
+        interval(250).
+        take(3).
+        map(function() {
+          var symbol = stockSymbols[Math.floor(Math.random() * stockSymbols.length)];
+          return {name: symbol, price: 30 + ((Math.floor(Math.random() * 100))/200), timeStamp: new Date()};
+        })
+
+  f(input, confirmPrint)
+  t.deepEqual(items, expected)
+  t.end()
+  //setTimeout(function() { f(stocks, print) }, 1000)
+
+})
diff --git a/test/solutions/27-stock-ticker.js b/test/solutions/27-stock-ticker.js
@@ -0,0 +1,19 @@
+module.exports = function (pricesNASDAQ, printRecord) {
+  var microsoftPrices,
+    now = new Date(),
+    tenDaysAgo = new Date( now.getFullYear(), now.getMonth(), now.getDate() - 10);
+
+  // use filter() to filter the trades for MSFT prices recorded any time after 10 days ago
+  microsoftPrices =
+    pricesNASDAQ.
+      filter(function (priceRecord) {
+        return priceRecord.name === 'MSFT' && priceRecord.timeStamp > tenDaysAgo;
+      });
+
+  // Print the trades to the output console
+  microsoftPrices.
+    forEach(function (priceRecord) {
+      printRecord(priceRecord);
+    });
+}
+