public void BasicTests()
{
Assert.AreEqual(218842, ProductOfLargestPair.MaxProduct(new int[] { 56, 335, 195, 443, 6, 494, 252 }));
Assert.AreEqual(194740, ProductOfLargestPair.MaxProduct(new int[] { 154, 428, 455, 346 }));
Assert.AreEqual(187827,
ProductOfLargestPair.MaxProduct(new int[]
{ 39, 135, 47, 275, 37, 108, 265, 457, 2, 133, 316, 330, 153, 253, 321, 411 }));
Assert.AreEqual(87984, ProductOfLargestPair.MaxProduct(new int[] { 136, 376, 10, 146, 105, 63, 234 }));
Assert.AreEqual(218536,
ProductOfLargestPair.MaxProduct(new int[]
{ 354, 463, 165, 62, 472, 53, 347, 293, 252, 378, 420, 398, 255, 89 }));
Assert.AreEqual(192672,
ProductOfLargestPair.MaxProduct(new int[] { 346, 446, 26, 425, 432, 349, 123, 269, 285, 93, 75, 14 }));
Assert.AreEqual(95680, ProductOfLargestPair.MaxProduct(new int[] { 134, 320, 266, 299 }));
Assert.AreEqual(139496,
ProductOfLargestPair.MaxProduct(
new int[] { 114, 424, 53, 272, 128, 215, 25, 329, 272, 313, 100, 24, 252 }));
Assert.AreEqual(174750, ProductOfLargestPair.MaxProduct(new int[] { 375, 56, 337, 466, 203 }));
}
public void ProductOfLargestPairRandom()
{
var rand = new Random();
var LIMIT = 1000;
Func <int[], int> myMaxProduct = delegate(int[] array)
{
var max = array[0];
var preMax = array[0];
for (var i = 1; i < array.Length; i++)
{
if (array[i] > max)
{
preMax = max;
max = array[i];
}
else
{
if (array[i] > preMax)
{
preMax = array[i];
}
}
}
return(max * preMax);
};
Func <int[], int, int[]> sample = delegate(int[] array, int size)
{
var i = array.Length;
int temp;
while (i-- > 0)
{
var index = rand.Next(0, i + 1);
temp = array[index];
array[index] = array[i];
array[i] = temp;
}
return(array.Take(size).ToArray());
};
var sw = Stopwatch.StartNew();
for (var i = 0; i < 199; i++)
{
var small = sample(Enumerable.Range(1, 5000).ToArray(), 500);
var big = sample(Enumerable.Range(5001, 20000).ToArray(), 10000);
var arr = small.Concat(big).ToArray();
Assert.AreEqual(myMaxProduct(arr), ProductOfLargestPair.MaxProduct(arr));
}
for (var i = 0; i < 200; i++)
{
var small = sample(Enumerable.Range(1, 5000).ToArray(), 500);
var big = sample(Enumerable.Range(10001, 40000).ToArray(), 10000);
var arr = small.Concat(big).ToArray();
Assert.AreEqual(myMaxProduct(arr), ProductOfLargestPair.MaxProduct(arr));
}
sw.Stop();
Console.WriteLine(sw.ElapsedMilliseconds + " ms");
Assert.IsTrue(sw.ElapsedMilliseconds < LIMIT, "Too slow! Speed must be lower than " + LIMIT + " ms. Maybe try a different approach?");
}