URL 1083. Factorials !!! (Read and understand), uralfactorials

URL 1083. Factorials !!! (Read and understand), uralfactorials

1083. Factorials !!!
Time limit: 1.0 second
Memory limit: 64 MB
Definition 1. N!!...! = N( N− K)( N−2 K)... ( NMod K), If KDoesn' t divide N; N!!...! = N( N− K)( N−2 K)... K, If KDivides N(There are KMarks! In the both cases ). Definition 2. XMod Y-A remainder after division XBy Y. For example, 10 mod 3 = 1; 3! = 3 · 2 · 1; 10 !!! = 10 · 7 · 4 · 1. Given numbers NAnd KWe have calculated a value of the expression in the first definition. Can you do it as well? Inputcontains the only line: one integer N, 1 ≤ N≤ 10, then exactly one space, then KExclamation marks, 1 ≤ K≤ 20. Outputcontains one number- N!!...! (There are KMarks! Here). Sample

Input	Output
9 !!	945

Problem Author:Oleg Katz
Problem Source:The 3rd high school children programming contest, USU, Yekaterinburg, Russia, March 4, 2001

Resolution: calculate the value based on the definition in the question.

AC code:

#include <bits/stdc++.h>using namespace std;int main(){    int n;    string s;    while(~scanf("%d", &n)){        cin>>s;        int k = s.size();        int ans = 1;        if(n % k){            int t = n / k;            for(int i=0; i<=t; i++){                ans *= (n - i * k);            }        }        else{            int t = n / k - 1;            for(int i=0; i<=t; i++){                ans *= (n - i * k);            }        }        printf("%d\n", ans);    }    return 0;}