1 files changed, 9 insertions, 0 deletions
diff --git a/math/binomial3.cpp b/math/binomial3.cpp
new file mode 100644
index 0000000..760f2eb
--- /dev/null
+++ b/math/binomial3.cpp
@@ -0,0 +1,9 @@
+ll calc_binom(ll n, ll k, ll p) {
+	if (n >= p || k > n) return 0;
+	ll x = k % 2 != 0 ? p-1 : 1;
+	for (ll c = p-1; c > n; c--) {
+		x *= c - k; x %= p;
+		x *= multInv(c, p); x %= p;
+	}
+	return x;
+}