improve/fix numbers

number/dual_number.hpp

@@ -1,3 +1,4 @@
+#pragma once
 #include <type_traits>
 
 namespace dual_number_ {

number/min_max_semiring.hpp

@@ -1,7 +1,8 @@
+#pragma once
 #include <limits>
 
 // min-max 半環（加法が min, 乗法が max, 零元が INF, 単位元が -INF）
-// Verified: abc236g
+// Verified: abc236g, abc388f
 template <class T> struct min_max_semiring {
     T val;
     min_max_semiring() : val(std::numeric_limits<T>::max()) {
@@ -21,6 +22,10 @@ template <class T> struct min_max_semiring {
     min_max_semiring &operator*=(const min_max_semiring &r) { return *this = *this * r; }
     bool operator==(const min_max_semiring &r) const { return this->val == r.val; }
     bool operator!=(const min_max_semiring &r) const { return !(*this == r); }
+    bool operator<(const min_max_semiring &r) const { return this->val < r.val; }
+    bool operator>(const min_max_semiring &r) const { return this->val > r.val; }
+    bool operator<=(const min_max_semiring &r) const { return this->val <= r.val; }
+    bool operator>=(const min_max_semiring &r) const { return this->val >= r.val; }
     template <class OStream> friend OStream &operator<<(OStream &os, const min_max_semiring &x) {
         return os << x.val;
     }

number/modint_mersenne61.hpp

@@ -17,7 +17,9 @@ class ModIntMersenne61 {
 
     ModIntMersenne61() : _v(0) {}
     // 0 <= x < md * 2
-    explicit ModIntMersenne61(long long x) : _v(x >= md ? x - md : x) {}
+    explicit ModIntMersenne61(long long x) : _v(x >= md ? x - md : x) {
+        assert(0 <= x and x < md * 2);
+    }
 
     long long val() const noexcept { return _v; }