最大的回文
本文关键字:回文 | 更新日期: 2023-09-27 17:56:41
我已经成功地确定了哪两个数字相乘时在 C# 中产生了一个数字回文,但是我需要从低到高对乘积进行排序。有没有办法这样做?
static void LargestPalindrome()
{
ulong product = 0;
ulong compare = 0;
for (uint i = 100; i < 1000; i++)
{
for (uint j = 100; j < 1000; j++)
{
product = i * j;
StringBuilder value = new StringBuilder(product.ToString());
//Pass string to reverse
string value_r = Reverse(value.ToString());
//Check if Numeric Palindrome
if(value_r.Equals(value.ToString()) && product>compare)
{
Console.WriteLine("{0} x {1} = {2} in reverse {3}", i, j, value, value_r);
}
}
}
}
不要打印出回文,而是将数字放在 List
以下就足够了。我只是对回文列表进行了排序,并将它们打印到控制台屏幕上。
static void LargestPalindrome()
{
ulong product = 0;
ulong compare = 0;
List<ulong> results = new List<ulong>();
for (uint i = 100; i < 1000; i++)
{
for (uint j = 100; j < 1000; j++)
{
product = i * j;
StringBuilder value = new StringBuilder(product.ToString());
//Pass string to reverse
string value_r = Reverse(value.ToString());
//Check if Numeric Palindrome
if(value_r.Equals(value.ToString()) && product>compare)
{
results.Add(product);
}
}
}
results.Sort();
foreach (var palindrome in results)
{
Console.WriteLine(palindrome);
}
}
您也可以使用 LINQ:
var palindromes = from i in Enumerable.Range(100, 9900)
from j in Enumerable.Range(100, 9900)
let product = (i * j)
where product.ToString() == new string(product.ToString().Reverse().ToArray())
orderby product
select product;