From 75a10aca7b10a0ea5ce632f49581ac1c80b84338 Mon Sep 17 00:00:00 2001
From: subcrip <contact@subc.rip>
Date: Mon, 28 Oct 2024 14:53:33 +0800
Subject: [PATCH] Add number/oint.cc

Signed-off-by: subcrip <contact@subc.rip>
---
 number/oint.cc | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)
 create mode 100644 number/oint.cc

diff --git a/number/oint.cc b/number/oint.cc
new file mode 100644
index 0000000..63050f4
--- /dev/null
+++ b/number/oint.cc
@@ -0,0 +1,28 @@
+template <typename T, T MDL, T MAX = INT_MAX>
+struct oint {
+    static_assert(MDL > MAX, "Number will never overflow because modulus is too small");
+    bool carry;
+    T val;
+    oint() : carry(0), val(0) {}
+    oint(const T& v) : carry(v > MAX), val(v % MDL) {}
+    friend oint operator*(const oint& a, const oint& b) {
+        oint res;
+        res.carry = a.carry | b.carry;
+        if (not res.carry and a.val > MAX / b.val) {
+            res.carry = 1;
+        }
+        res.val = (a.val * b.val) % MDL;
+        return res;
+    }
+    friend oint operator+(const oint& a, const oint& b) {
+        oint res;
+        res.carry = a.carry | b.carry;
+        if (not res.carry and a.val > MAX - b.val) {
+            res.carry = 1;
+        }
+        res.val = (a.val + b.val) % MDL;
+        return res;
+    }
+    oint& operator+=(const oint& rhs) { return *this = *this + rhs; }
+    oint& operator*=(const oint& rhs) { return *this = *this * rhs; }
+};