07.C# - 알고리즘 : 수열 구하기

예제1 : 1 - 2 + 3 - 4 + 5 ... +99 - 100 = ? 구하기

using System;

public class 간단수열
{
    public static void Main(string[] args)
    {
        int total = 0;
        for (int i = 1; i <= 100; i++)
        {
            if (i % 2 == 1)
            {
                total += i;
            }

            if (i % 2 == 0)
            {
                total -= i;
            }

        }
        Console.WriteLine("{0}", total);
    }   
}

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예제2 : 1/2 - 2/3 + 3/4 ... -99/99 + 99/100 = ?

using System;

public class 수열문제
{
    public static void Main()
    {
        //[1] Input
        double sum = 0.0;

        //[2] Process
        for (int i = 1; i <= 99; i++)
        {
            if (i % 2 != 0)
            {
                sum +=  i  / (double)(i + 1);
            }
            else
            {
                sum -=  i  / (double)(i + 1);
            }
        }

        //[3] Output
        Console.WriteLine("{0}", sum);
    }
}

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예제3 : 1 + 2 + 4 + 7 + 11 + 16 + 22 + ...

using System;

public class 수열퀴즈
{
    public static void Main(string[] args)
    {
        //[1] Input
        int index = 0;
        int data = 1;
        int sum = 0;

        //[2] Process
        for (int i = 0; i < 20; i++)
        {
            Console.Write("{0} + ", data);
            sum += data;//1누적
            data = data + (i + 1); //다음번에 index를 더함   
        }

        //[3] Output
        Console.WriteLine("\n");
        Console.WriteLine(sum);
    }   
}

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7.수열.zip