HDOJ u Calculate e

Description

A simple mathematical formula for e is 



where n is allowed to go to infinity. This can actually yield very accurate approximations of e using relatively small values of n. 

 

Output

Output the approximations of e generated by the above formula for the values of n from 0 to 9. The beginning of your output should appear similar to that shown below. 

 

Sample Output

        
        
        
        

         
         
         
          n e
- -----------
0 1
1 2
2 2.5
3 2.666666667
4 2.708333333 
        
        
        
        

 

#include <stdio.h>
int main()
{
    int n, i;
    double e, x = 1;
    printf("n e\n- -----------\n");
    for(i = 0; i <= 9; i++)
    {
        if(i==0)
            e = 1;
        else
        {
            x = x / i;
            e = e + x;
        }
        if(i==0)
            printf("0 1\n");
        else if(i==1)
            printf("1 2\n");
        else if(i==2)
            printf("2 2.5\n");
        else
            printf("%d %.9lf\n",i, e);
    }
    return 0;
}