C#Á·Ï°ÊµÏÖ¼òµ¥¸Ä½øËÄÔòÔËËã

using System;
using System.Linq;
using System.Data;

namespace day15test03
{
    class Program
    {
        /// <summary>
        /// ËÄÔòÔËËã¼ÆËãÆ÷
        /// </summary>
        /// <param name="args"></param>
        static void Main(string[] args)
        {
            //Console.WriteLine("ÊäÈëÒª¼ÆËãµÄʽ×Ó£¨µÈºÅ½áβ¼´¿É,ÀàËÆ 1+21*6-8/4+4-55*6+4/5=£©£º");
            //String str = Console.ReadLine();
            Suan("1/2+4+5/6=");
        }
        //ÔËË㣬µ÷ÓüӼõºÍ³Ë³ýÔËËã
        public static void Suan(String sss)
        {
            String ss = sss.TrimStart('0'), s1 = "", s = "";
            DataTable dt = new DataTable();
            if (ss.IndexOf("*") != -1 && ss.IndexOf("/") != -1) { s1 = yunSuan(yunSuan(ss, "*"), "/"); s = dt.Compute(s1.Replace("=", ""), "").ToString(); }
            else if(ss.IndexOf("*") != -1 && ss.IndexOf("/") == -1) { s1 = yunSuan(ss, "*"); s = dt.Compute(s1.Replace("=", ""), "").ToString(); }
            else if(ss.IndexOf("*") == -1 && ss.IndexOf("/") != -1) { s1 = yunSuan(ss, "/"); s = dt.Compute(s1.Replace("=", ""), "").ToString(); }
            else { s = dt.Compute(ss.Replace("=", ""), "").ToString(); }
            Console.WriteLine(ss + s);
        }
        //ÔËËã
        private static String yunSuan(String ss, String tt)
        {
            float[] nums = new float[10];
            int count1 = 0;
            String ss1 = "";
            String[] s1 = new String[10];
            if(ss == null) { return null; }
            if (ss.IndexOf(tt) != -1)
            {
                s1[0] = ss;
                int[] nn = getFuhao(ss, tt);
                for (int x = 0; x < nn.Length; x++)
                {
                    if (nn[x] > 0) { count1++; }
                }
                for (int i = 0; i < count1; i++)
                {
                    { nums[i] = getCheng(s1[i], getFuhao(s1[i], tt)[1], tt, ref ss1); s1[i + 1] = s1[i].Replace(ss1, nums[i].ToString()); }
                }
            }
            return s1[count1];
        }
        ·µ»ØÔËËã·ûµÄλÖÃ
        private static int[] getFuhao(String ss, String stt)
        {
            int[] num = new int[5];
            for (int i = 1; i < 5; i++)
            {
                if (ss.IndexOf(stt, num[i - 1] + 1) != -1) { num[i] = ss.IndexOf(stt, num[i - 1] + 1); }
                else { break; }
            }
            return num;
        }
        //³Ë³ýÔËËã
        private static float getCheng(String ss, int n, String t, ref String ing)
        {
            int[] left = new int[ss.Length];
            int[] right = new int[ss.Length];
            int c = 0, d = 0;
            for (int i = 1; i < ss.Length; i++)
            {
                if (n >= i && c == 0 && int.TryParse(ss[n - i].ToString(), out left[i - 1])) { }
                else if (n >= i && ss[n - i] == '.' && c == 0) { left[i - 1] = 46; }
                else { c++; left[i - 1] = -1; }
                if (d == 0 && int.TryParse(ss[n + i].ToString(), out right[i - 1])) { }
                else if (d == 0 && ss[n + i] == '.') { right[i - 1] = 46; }
                else { d++; right[i - 1] = -1; }
                if (c != 0 && d != 0) { break; }
            }
            float a = get2(left, 1);
            float b = get2(right, 2);
            ing = a.ToString() + t + b.ToString();
            if (t == "*") { return (float)Math.Round(a * b, 2); }
            else if (t == "+") { return (float)Math.Round(a + b, 2); }
            else if (t == "-") { return (float)Math.Round(a - b, 2); }
            else
            {
                try { return (float)Math.Round(a / b, 2); }
                catch { Console.WriteLine("³ýÊý²»ÄÜΪÁ㣡"); return -1; }
            }
        }
        //·µ»ØÈ¡³öµÄÔËËã·ûµÄÁ½±ßµÄÊý
        private static float get2(int[] right, int a)
        {
            int count = 0, num = 0;
            float sum;
            for (int j = 1; j < right.Length-1; j++)
            {
                if (right[j] == 46) { num = j; }
                if (right[j] != -1 && right[j + 1] != 0 || right[j] != -1 && right[j - 1] != 0 || right[j] != -1 && right[j + 1] == 0 && right[j - 1] == 0)
                { count++; }
                else { break; }
            }
            count++;
            int[] nums = new int[count];
            for (int i = 0; i < count; i++) { nums[i] = right[i]; }
            if (num == 0)
            {
                if (a == 1) { sum = int.Parse(String.Concat(String.Join("", nums).ToCharArray().Reverse())); }
                else { sum = int.Parse(String.Concat(String.Join("", nums))); }
            }
            else
            {
                if (a == 1) { sum = float.Parse(String.Concat(String.Join("", nums).Replace("46", ".").ToCharArray().Reverse())); }
                else { sum = float.Parse(String.Join("", nums).Replace("46", ".")); }
            }
            return (float)Math.Round(sum, 2);
        }
    }
}