Converting strings to Integers-a simple challenge for hero Pang Guo

Just idle, I went around csdn and saw this programming challenge: Converting strings to integers. The requirements are as follows:

Question details

Enter a string that represents an integer, convert it to an integer, and output it. For example, if the input string is "345", the output integer is 345.

Complete the strtoint function to convert a string to an integer.

Reminder:

Before submitting the code, please review your program. For example, if the given string is shown in the picture on the left, are you sure you want to take it into consideration?

Of course, the correct output corresponding to each of them is shown in the picture on the right (assuming that you are in a 32-bit System and the compiling environment is vs2008 or above)

I haven't done this kind of question for a long time. The question should be completed in Java, C, C ++, C. of course, I chose C #. I tried it. below is the code I submitted and I don't expect to win the prize, because hundreds of people have submitted the correct solution (that is, the challenge is successful)

using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;namespace test{    class Program    {        static void Main(string[] args)        {            string[] ar = { "", "1", "+1", "-1", "123", "-123", "010", "+00131204", "-01324000", "2147483647", "-2147483648", "-2147483649", "2147483648", "-2147483648", "abc", "-abc", "1a", "23a8f", "-3924x8fc", "   321", "   -321", "123  456", "123   ", "   -321", "   +4488", "  +  4488", "  +  413", "  ++c", " ++1", " --2", "    -2" };            foreach (var s in ar)            {                Console.WriteLine("{0}->{1}", s, StrToInt(s));            }            Console.Read();        }        static int StrToInt(string str)        {            if (str == null)            {                throw new ArgumentException("str can't be null!");            }            if (str == "")            {                return 0;            }            str=str.Trim();            bool singed = false;            int index = 0;            if (str[0] == '-' || str[0] == '+')            {                singed = true;                index = 1;            }            int length = str.Length;            int n = 0;            while (index < length)            {                if (char.IsNumber(str[index]))                {                    n = n * 10 + (str[index++] - '0');                    if (n < 0)                    {                        if (singed)                        {                            if (str[0] == '+')                            {                                return 2147483647;                            }                            else                            {                                return -2147483648;                            }                        }                        else                        {                            return 2147483647;                        }                                            }                }                else                {                    break;                }            }            if (singed && str[0] == '-')            {                n *= -1;            }            return n;        }    }}

I haven't written C # for a long time. I just want to entertain myself. .