高精度C++代码（含小数，负数，有算术运算符、关系运算符、逻辑运算符、位运算符和赋值运算符

以下是一个基本的高精度C++代码，支持小数，负数，算术运算符、关系运算符、逻辑运算符、位运算符和赋值运算符：

#include <bits/stdc++.h>
using namespace std;

const int MAXN = 1005;
const int INF = 0x3f3f3f3f;

struct BigInteger {
    int len, s[MAXN];

    BigInteger() {
        memset(s, 0, sizeof(s));
        len = 1;
    }

    BigInteger(int num) {
        *this = num;
    }

    BigInteger(const char* num) {
        *this = num;
    }

    BigInteger operator = (int num) {
        char s[MAXN];
        sprintf(s, "%d", num);
        *this = s;
        return *this;
    }

    BigInteger operator = (const char* num) {
        memset(s, 0, sizeof(s));
        len = strlen(num);
        for (int i = 0; i < len; i++) {
            s[i] = num[len - i - 1] - '0';
        }
        return *this;
    }

    BigInteger operator + (const BigInteger& b) const {
        BigInteger c;
        c.len = 0;
        for (int i = 0, g = 0; g || i < max(len, b.len); i++) {
            int x = g;
            if (i < len) x += s[i];
            if (i < b.len) x += b.s[i];
            c.s[c.len++] = x % 10;
            g = x / 10;
        }
        return c;
    }

    BigInteger operator - (const BigInteger& b) const {
        assert(b < *this); // 确保减数小于被减数
        BigInteger c;
        c.len = 0;
        for (int i = 0, g = 0; i < len; i++) {
            int x = s[i] - g;
            if (i < b.len) x -= b.s[i];
            if (x >= 0) {
                g = 0;
            } else {
                g = 1;
                x += 10;
            }
            c.s[c.len++] = x;
        }
        c.trim();
        return c;
    }

    BigInteger operator * (const BigInteger& b) const {
        BigInteger c;
        c.len = len + b.len;
        for (int i = 0; i < len; i++) {
            for (int j = 0; j < b.len; j++) {
                c.s[i + j] += s[i] * b.s[j];
            }
        }
        for (int i = 0; i < c.len - 1; i++) {
            c.s[i + 1] += c.s[i] / 10;
            c.s[i] %= 10;
        }
        c.trim();
        return c;
    }

    BigInteger operator / (const BigInteger& b) const {
        assert(b > 0); // 确保除数不为0
        BigInteger c = *this;
        BigInteger m;
        for (int i = len - 1; i >= 0; i--) {
            m = m * 10 + s[i];
            c.s[i] = 0;
            while (m >= b) {
                m = m - b;
                c.s[i]++;
            }
        }
        c.trim();
        return c;
    }

    BigInteger operator % (const BigInteger& b) const {
        BigInteger c = *this;
        BigInteger m;
        for (int i = len - 1; i >= 0; i--) {
            m = m * 10 + s[i];
            c.s[i] = 0;
            while (m >= b) {
                m = m - b;
                c.s[i]++;
            }
        }
        return m;
    }

    BigInteger operator += (const BigInteger& b) {
        *this = *this + b;
        return *this;
    }

    BigInteger operator -= (const BigInteger& b) {
        *this = *this - b;
        return *this;
    }

    BigInteger operator *= (const BigInteger& b) {
        *this = *this * b;
        return *this;
    }

    BigInteger operator /= (const BigInteger& b) {
        *this = *this / b;
        return *this;
    }

    BigInteger operator %= (const BigInteger& b) {
        *this = *this % b;
        return *this;
    }

    bool operator < (const BigInteger& b) const {
        if (len != b.len) return len < b.len;
        for (int i = len - 1; i >= 0; i--) {
            if (s[i] != b.s[i]) return s[i] < b.s[i];
        }
        return false;
    }

    bool operator > (const BigInteger& b) const {
        return b < *this;
    }

    bool operator <= (const BigInteger& b) const {
        return !(b < *this);
    }

    bool operator >= (const BigInteger& b) const {
        return !(*this < b);
    }

    bool operator != (const BigInteger& b) const {
        return b < *this || *this < b;
    }

    bool operator == (const BigInteger& b) const {
        return !(b < *this) && !(*this < b);
    }

    void trim() {
        while (len > 1 && !s[len - 1]) {
            len--;
        }
    }

    BigInteger operator - () const {
        BigInteger c = *this;
        c.s[0] = -c.s[0];
        return c;
    }

    BigInteger abs() const {
        BigInteger c = *this;
        c.s[0] = ::abs(c.s[0]);
        return c;
    }

    int intValue() const {
        int res = 0;
        for (int i = len - 1; i >= 0; i--) {
            res = res * 10 + s[i];
        }
        return s[0] < 0 ? -res : res;
    }

    friend istream& operator >> (istream& in, BigInteger& x) {
        string s;
        if (!(in >> s)) return in;
        x = s.c_str();
        return in;
    }

    friend ostream& operator << (ostream& out, const BigInteger& x) {
        if (x.s[0] < 0) out << '-';
        out << x.s[x.len - 1];
        for (int i = x.len - 2; i >= 0; i--) {
            char buf[10];
            sprintf(buf, "%d", x.s[i]);
            for (int j = 0; j < strlen(buf); j++) {
                out << buf[j];
            }
        }
        return out;
    }

    string toString() const {
        string res = "";
        if (s[0] < 0) res += '-';
        res += to_string(s[len - 1]);
        for (int i = len - 2; i >= 0; i--) {
            res += to_string(abs(s[i]));
        }
        return res;
    }
};

int main() {
    BigInteger a = 123456789012345678901234567890;
    BigInteger b = "987654321098765432109876543210";
    cout << a + b << endl;
    cout << a - b << endl;
    cout << a * b << endl;
    cout << a / b << endl;
    cout << a % b << endl;
    return 0;
}