public static Mint nCkForBigNSmallK(long n, long k)
{
Mint x = 1; Mint y = 1; for (int i = 0; i < k; i++)
{
x *= n - i; y *= i + 1;
}
return(x / y);
}
} } public class Combination { static long SIZE = (long)1e7 + 1; static Mint[] mFactorial, mFactrialInverse, mInverse; private static void Init()
{
mFactorial = new Mint[SIZE]; mFactrialInverse = new Mint[SIZE]; mInverse = new Mint[SIZE]; mFactorial[0] = mFactorial[1] = 1; mFactrialInverse[0] = mFactrialInverse[1] = 1; mInverse[1] = 1; for (int i = 2; i < SIZE; i++)
{
mFactorial[i] = mFactorial[i - 1] * i; mInverse[i] = -1 * mInverse[Mint.MOD % i] * (Mint.MOD / i); mFactrialInverse[i] = mFactrialInverse[i - 1] * mInverse[i];
}
}