取n个数当中最小的3个数的算法

Question

取n（n>3）个数当中最小的3个数，求C#中可以实现的比较好一点的算法。
例如：有一数组a[n]，取出其中最小的3个数的值及其下标。

Answer 1

有一数组的话直接
Arrays.sort(array);
取索引为0，1，2的就行了

Answer 2

堆排序；算法复杂度：n*log2(n);

Answer 3

http://topic.csdn.net/u/20090528/20/b37348e6-d2be-429d-a02f-e2bdac23c173.html

Answer 4

        int v[]={4,3,5,6,8,9,7,2,10,1};
        int x1=v[0],b1=0;//b1下标
        int x2=v[0],b2=0;
        int x3=v[0],b3=0;//x1=>x2=>x3
        int b;
        for(int loop=1,lmax=v.length;loop<lmax;loop++){
            b = v[loop];
            if(b<x1){
                if(b<x2){
                    x1=x2;
                    b1=b2;
                    if(b<x3){
                        x2=x3;
                        b2=b3;
                        x3=b;
                        b3=loop;
                    }else{
                        x2=b;
                        b2=loop;
                    }
                }else{
                    x1=b;
                    b1=loop;
                }
            }
        }

Answer 5

x1 x2 x3是最小值
b1 b2 b3是对应下标

Answer 6

 class Program
    {
        static void Main(string[] args)
        {
            int[] a ={ 20, 12, 25, 32, 56, 58, 14, 65, 98, 10 };
            int[] b = { 20, 12, 25, 32, 56, 58, 14, 65, 98, 10 };
            Array.Sort(a); 
            int i, j=0;
            while (j<3)
            {
            for (i = 0; i < 10; i++)
            {
                if (b[i] != a[j])
                    continue;
                else
                  Console.WriteLine("a[{0}]=={1}", i, a[j]);
                    j++;
            }
            }
                Console.ReadLine();
        }
    }
}           这是我刚刚写的一个，希望对你又帮助！

Answer 7

    class Program
    {
        static void Main(string[] args)
        {
            List<MyValue> lists = new List<MyValue>();
            int[] arr = new int[8] { 12, 58, 65, 44, 7, 1, 98, 54 };
            for (int i = 0; i < arr.Length; i++)
            {
                lists.Add(new MyValue(arr[i], i));
            }
            for (int i = 0; i < lists.Count; i++)
            {
                for (int j = i + 1; j < lists.Count; j++)
                {
                    if (lists[i].Value < lists[j].Value)
                    {
                        MyValue value1 = lists[j];
                        lists[j] = lists[i];
                        lists[i] = value1;
                    }
                }
            }
            Console.WriteLine("最小的三个值为：");
            for (int i = lists.Count-1; i >=lists.Count-3; i--)
            {
                Console.WriteLine("第{0}位：{1}",lists[i].Position,lists[i].Value);
            }
            Console.ReadLine();
        }
    }    class MyValue
    {
        public MyValue(int value, int position)
        {
            this._value = value;
            this._position = position;
        }        private int _value;
        private int _position;        public int Value
        {
            get
            { return _value; }
            set
            { _value = value; }
        }        public int Position
        {
            get
            { return _position; }
            set
            { _position = value; }
        }
    }