C Programming Tutorial

 
 
 
 
#include<stdio.h>
#includde<conio.h>    

void main()
{

    int n,i,sum=0;
    clrscr();
    printf(\"\\n PLEASE ENTER THE VALUE OF N: \");
    scanf(\"%d\",&n);
    printf(\"\\n\\n SUM = \");
    for(i=1;i<=n;i++)
    {
        if(i%2==1)
        {
            if(i==1)
                sum=1;
            else
                sum=sum-i*i;
            if(i==n)
            printf(\"%d\",i*i);
            else
            printf(\"%d + \",i*i);
        }
        else
        {
            sum=sum+i*i;
            if(i==n)
            printf(\"%d\",i*i);
            else
            printf(\"%d - \",i*i);
         }
     }
     printf(\"\\n THE SUM IS %d\",sum);

     getch();
}



*************************** OUTPUT ************************


 PLEASE ENTER THE VALUE OF N: 6


 SUM = 1 + 4 - 9 + 16 - 25 + 36
 THE SUM IS 23

 PLEASE ENTER THE VALUE OF N: 7

 SUM = 1 + 4 - 9 + 16 - 25 + 36 - 49
 THE SUM IS -26


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