Biginteger/decimal

2026-08-16 14:55:25 +08:00
parent abd82e6961
commit 5b3320e65c
8 changed files with 975 additions and 6 deletions
@@ -0,0 +1,69 @@
+#pragma once
+
+#include <string>
+
+namespace bstl {
+
+class BigInteger {
+public:
+    BigInteger();
+    BigInteger(int value);
+    BigInteger(long long value);
+    BigInteger(unsigned long long value);
+    explicit BigInteger(const std::string& value);
+    explicit BigInteger(const char* value);
+    BigInteger(const BigInteger& other) = default;
+    BigInteger& operator=(const BigInteger& other) = default;
+
+    bool isZero() const;
+    int sign() const;
+    std::string toString() const;
+
+    bool operator==(const BigInteger& other) const;
+    bool operator!=(const BigInteger& other) const;
+    bool operator<(const BigInteger& other) const;
+    bool operator>(const BigInteger& other) const;
+    bool operator<=(const BigInteger& other) const;
+    bool operator>=(const BigInteger& other) const;
+
+    bool operator==(int value) const;
+    bool operator!=(int value) const;
+    bool operator<(int value) const;
+    bool operator>(int value) const;
+    bool operator<=(int value) const;
+    bool operator>=(int value) const;
+
+    bool operator==(long long value) const;
+    bool operator!=(long long value) const;
+    bool operator<(long long value) const;
+    bool operator>(long long value) const;
+    bool operator<=(long long value) const;
+    bool operator>=(long long value) const;
+
+    BigInteger operator+() const;
+    BigInteger operator-() const;
+    BigInteger& operator+=(const BigInteger& other);
+    BigInteger& operator-=(const BigInteger& other);
+    BigInteger& operator*=(const BigInteger& other);
+    BigInteger& operator/=(const BigInteger& other);
+
+    BigInteger operator+(const BigInteger& other) const;
+    BigInteger operator-(const BigInteger& other) const;
+    BigInteger operator*(const BigInteger& other) const;
+    BigInteger operator/(const BigInteger& other) const;
+
+private:
+    std::string digits_;  // 无符号数字，从高位到低位
+    int sign_;            // -1, 0, 1
+
+    static std::string trimLeadingZeros(const std::string& value);
+    static int compareAbs(const std::string& a, const std::string& b);
+    static std::string addAbs(const std::string& a, const std::string& b);
+    static std::string subAbs(const std::string& a, const std::string& b);
+    static std::string mulAbs(const std::string& a, const std::string& b);
+    static std::string divAbs(const std::string& a, const std::string& b);
+};
+
+using BitInteger = BigInteger;
+
+} // namespace bstl