From 2b2f8b1ef1c6eadb131fd8100be15106ef901ac3 Mon Sep 17 00:00:00 2001
From: JJCUBER <34446698+JJCUBER@users.noreply.github.com>
Date: Fri, 3 Apr 2026 06:39:29 -0400
Subject: [PATCH] Add missing const in cf hashing

Without operator ull() being marked const, it causes a compilation error on some compilers due to const functions operator==, operator< calling it.
---
 content/strings/Hashing-codeforces.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/content/strings/Hashing-codeforces.h b/content/strings/Hashing-codeforces.h
index 5129112db..7b1a3dcb4 100644
--- a/content/strings/Hashing-codeforces.h
+++ b/content/strings/Hashing-codeforces.h
@@ -21,7 +21,7 @@ struct A {
 	A operator+(A o){int y = x+o.x; return{y - (y>=M)*M, b+o.b};}
 	A operator-(A o){int y = x-o.x; return{y + (y< 0)*M, b-o.b};}
 	A operator*(A o) { return {(int)(1LL*x*o.x % M), b*o.b}; }
-	explicit operator ull() { return x ^ (ull) b << 21; }
+	explicit operator ull() const { return x ^ (ull) b << 21; }
 	bool operator==(A o) const { return (ull)*this == (ull)o; }
 	bool operator<(A o) const { return (ull)*this < (ull)o; }
 };