提供四种方法，第四种是C#3.0以上才有的linq
static void Main(string[] args)
{
int[] arrA = new int[short.MaxValue];
int[] arrB = new int[short.MaxValue];
Random r = new Random(Environment.TickCount);
for (int i = 0; i < short.MaxValue; i++)
{
arrA[i] = r.Next(0, int.MaxValue);
arrB[i] = r.Next(0, int.MaxValue);
}
//以上是构建数据
int tick = Environment.TickCount;
GetSameItem1(arrA, arrB);
Console.WriteLine(Environment.TickCount - tick);
tick = Environment.TickCount;
GetSameItem2(arrA, arrB);
Console.WriteLine(Environment.TickCount - tick);
tick = Environment.TickCount;
GetSameItem3(arrA, arrB);
Console.WriteLine(Environment.TickCount - tick);
tick = Environment.TickCount;
GetSameItem4(arrA, arrB);
Console.WriteLine(Environment.TickCount - tick);
}
static List<int> GetSameItem1(int[] arrA, int[] arrB)
{
List<int> list = new List<int>();
foreach (int i in arrA)
if (Array.IndexOf(arrB, i) > -1)
list.Add(i);
return list;
}
static List<int> GetSameItem2(int[] arrA, int[] arrB)
{
List<int> list = new List<int>(arrA);
foreach (int i in arrB)
list.Remove(i);
return list;
}
static List<int> GetSameItem3(int[] arrA, int[] arrB)
{
Dictionary<int, bool> dic = new Dictionary<int, bool>();
List<int> list = new List<int>();
foreach (int i in arrA)
{
if (dic.ContainsKey(i))
{
dic[i] = true;
list.Add(i);
}
else
dic.Add(i, false);
}
foreach (int i in arrB)
{
if (dic.ContainsKey(i))
{
dic[i] = true;
list.Add(i);
}
else
dic.Add(i, false);
}
return list;
}
static List<int> GetSameItem4(int[] arrA, int[] arrB)
{
return arrA.Intersect(arrB).ToList();
}
