Hdoj 2156 Fractional Matrix

Fractional matrix

Time limit:2000/1000 MS (java/others) Memory limit:32768/32768 K (java/others)
Total submission (s): 4580 Accepted Submission (s): 2769

Problem description We define the following matrices:
1/1 1/2 1/3
1/2 1/1 1/2
1/3 1/2 1/1
The element on the diagonal of the matrix is always 1/1, and the denominator of the scores on both sides of the diagonal increments.
Request the sum of this matrix.

Input is given an integer n (n<50000) per line, indicating that the matrix is n*n. When N is 0 o'clock, the input ends.

Output outputs an answer that retains 2 decimal places.

Sample Input12340

Sample Output1.003.005.678.83 Code:

#include "stdio.h" int main () {    int n;    Double sum,i;    while (scanf ("%d", &n) &&n)    {        sum=n;        i=2;        while (n--)            sum+= (1/i++) *n*2;        printf ("%.2lf\n", sum);}    }

Hdoj 2156 Fractional Matrix