HDU 1012 u Calculate e

该题只要注意前面几个精度就可以。

#include<stdio.h>

#include<stdlib.h>

int main()

{

    int n=1,a[10]={1};

    while( n<10 )

    {

     a[n]=a[n-1]*n;

     n++;

     }

    printf( "n e\n" );

    printf( "- -----------\n" );

    printf( "0 1\n" );

    printf( "1 2\n" );

    printf( "2 2.5\n" );

    n=3;

    double t=2.5;  

    while( n<10 )

    {

           t+=1.0/a[n];

           printf( "%d %.9lf\n",n,t ); 

           n++;  

    }

   // system( "pause" );

    return 0;    

}