From 639b71d230087a9104318763ef74519f83f9248f Mon Sep 17 00:00:00 2001
From: hitonanode <32937551+hitonanode@users.noreply.github.com>
Date: Mon, 12 May 2025 23:00:20 +0900
Subject: [PATCH] add inv() to acl_fac

---
 number/acl_modint.hpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/number/acl_modint.hpp b/number/acl_modint.hpp
index 88a15af4..77964ea6 100644
--- a/number/acl_modint.hpp
+++ b/number/acl_modint.hpp
@@ -28,5 +28,6 @@ template <typename modint> struct acl_fac {
     }
     modint operator[](int i) const { return facs[i]; }
     modint finv(int i) const { return facinvs[i]; }
+    modint inv(int i) const { return i > 0 ? facinvs[i] * facs[i - 1] : 1; }
 };
 // acl_fac<mint> fac(1000000);