2014年02月14日 01:03

pahkey

Stopwatch sw1 = Stopwatch.StartNew();
int cnt = Enumerable.Range(1, 10000).Sum(k => k.ToString().Count(z => z == '8'));
sw1.Stop();
Console.WriteLine($"Elapsed MillSecond : {sw1.ElapsedMilliseconds}, Value : {cnt}");

Elapsed MillSecond : 4, Value : 4000

c# 입니다.

int cnt = 0;
for(int i = 0 ; i < 10000; i++)
 for(int j = 0; j < i.ToString().Length; j++)
 if (i.ToString()[j].ToString().Contains("8")) cnt++;
System.Console.WriteLine("cnt : " +cnt);

using System;
class Program
{
 static void Main(string[] args)
 {
 int numberEightCount = 0;
 for (int i = 1; i <= 10000; i++)
 {
 char[] digits = i.ToString().ToCharArray();
 foreach (var aDigit in digits)
 {
 if (aDigit == '8')
 {
 numberEightCount++;
 }
 }
 }
 Console.WriteLine("numberEightCount = " + numberEightCount);
 }
}

C#으로 작성했습니다. 7에서 9 milliseconds 정도 걸렸습니다.

using System.Linq;
 public int CountEights(int n)
 {
 var sum = 0;
 for (int i = 0; i <= n; i++)
 sum += i.ToString().Count(e => e.ToString().Contains('8'));
 return sum;
 }

저는 좀 특이하게 ! (? ᄏᄏ)

 static void Main(string[] args)
 {
 int result = 0;
 for(int i = 1;i<= 10000;i++)
 {
 char[] value = i.ToString().ToArray();
 for(int z = 0; z<value.Length;z++)
 {
 if(value[z] == '8')
 {
 result++;
 }
 }
 }
 Console.WriteLine(result);
 }

static void Main(string[] args)
 {
 Console.WriteLine(Answer(8,10000));
 }
static int Answer(int findNum,int numMax)
 {
 string sum = "";
 for (int i = 1; i <= numMax ; i++)
 {
 sum += i;
 }
 int answer = sum.Length - sum.Replace(findNum.ToString(), "").Length;
 return answer;
 }

public void CountEIGHTOneToTenThousand()
 {
 int cnt9 = 0;
 for (int i = 1; i <= 10000; i++)
 {
 string Num = Convert.ToString(i);
 foreach (char num in Num)
 {
 if (num == '9')
 cnt9++;
 }
 }
 Console.WriteLine(cnt9);
 } 

비슷한 문제가 하나 있었는데, 그 코드를 재활용한겁니다

int result = 0;
 for (int i = 1; i <= 10000; i++)
 {
 int temp = i;
 while (temp != 0)
 {
 if(temp % 10 == 8)
 {
 result++;
 }
 temp /= 10;
 }
 }
 Console.WriteLine($"result : {result}");

 static void Main(string[] args)
 {
 try
 {
 int count = 0;
 char[] chArray = null;
 for(int i = 0; i < 10000; i++)
 {
 chArray = i.ToString().ToCharArray();
 foreach (var p in chArray)
 {
 if (p.Equals('8'))
 {
 count++;
 }
 }
 }
 Console.WriteLine(count);
 }
 catch(Exception ex)
 {
 Console.WriteLine(ex.Message);
 }
 finally
 {
 Console.ReadKey();
 }
 }

string strNum;
int cnt = 0;
for (int i = 1; i <= 10000; i++)
{
 strNum = i.ToString();
 foreach (char a in strNum)
 {
 if (a == '8') cnt++;
 }
}