Console.WriteLine("請輸入一個字串！");

string sString = Console.ReadLine();

StringBuilder a = new StringBuilder();

for (int i = sString.Length - 1; i >= 0; i--)

{

a.Append(sString[i]);

}

if (sString.Equals(a.ToString()))

Console.WriteLine("是迴文");

else

Console.WriteLine("不是迴文");

Console.ReadLine();

2.直接在單個字串裡面進行處理，透過比較

Console.WriteLine("請輸入一個字串！");

string s = Console.ReadLine();

int half = s.Length / 2;

int len = s.Length;

for (int i = 0; i < half; i++)

{

if (s[i] != s[len - i - 1])

{

Console.WriteLine("Congratulations,It is not a palindrome");

return;

}

}

Console.WriteLine("Sorry,It is a palindrome");

3.先求出整數上各位置的數字，有點白痴。。。

int a = 123456789;

int b=1;

int d=a/10;

while (d!= 0)

{

d = d / 10;

b++;//位數

}

int[] array = new int[b];

for(int c=b;c>0;c--)

{

array[c-1] = a /Convert.ToInt32((Math.Pow(Convert.ToDouble(10), Convert.ToDouble(c-1)))) ;

a = a % Convert.ToInt32((Math.Pow(Convert.ToDouble(10), Convert.ToDouble(c - 1))));

Console.WriteLine(array[c-1].ToString());

}