/* Canadian Computing Competition
Example program to demonstrate input and output and time limit.
Programming Language: C++
Specification:
Write a program that reads several positive integers, one per
line. For each integer n, output the number of orderings
possible for a set of n distinct values. n will not exceed 11.
The last line of input is indicated with n being 0.
Sample Input:
1
11
0
Output for Sample Input:
1
39916800
Implementation:
The answer is n! (n factorial) which is easily computed in n steps.
But this program does it the hard way. It uses a recursive function
to enumerate and count all the possible orderings.
How to run the program:
The program reads from "standard input" and writes to "standard output."
That is, compile such as:
g++ test.cc
Then run the program as:
./a.out < input.txt
or, if you wish to just type numbers at the program, run by
./a.out
Run-time:
Please time the execution time of this program on your computer,
using the sample input. This time is the maximum that should be
allowed for any CCC program.
On a 350 MHz processor, this program runs in about 15 seconds.
(Your results will vary depending on processor, compiler, and
compiler options.)
*/
#include
#include
using namespace std;
int countfact(vector &set, int n, int total) {
int ret = 0;
if (n == 0) {
/* uncomment to print out each ordering */
// /*
for (int j=0; j set(11);
int n;
for( int i = 0; i < 11; i++ ) set[i] = i+1;
while( cin >> n && n != 0 ) {
cout << countfact(set, n, n) << endl;
}
}