C++ 中大小为 N 且元素为正整数且和为 K 的数组个数

#include <bits/stdc++.h>
using namespace std;
int factorial(int n) {
   int result = 1;
   for (int i = 2; i <= n; i++) {
      result *= i;
   }
   return result;
}
int getNumberOfArraysCount(int n, int k) {
   return factorial(n) / (factorial(k) * factorial(n - k));
}
int main() {
   int N = 5, K = 8;
   cout << getNumberOfArraysCount(K - 1, N - 1) << endl;
   return 0;
}