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OI-codes/templates/BigInt.h
2021-10-25 20:18:54 +08:00

202 lines
5.6 KiB
C++

#include <algorithm>
#include <iostream>
#include <string>
class BigInt {
public:
int sign;
std::string s;
BigInt() {
s = "";
}
BigInt(std::string x) {
*this = x;
}
BigInt(int x) {
*this = std::to_string(x);
}
BigInt negative() {
BigInt x = *this;
x.sign *= -1;
return x;
}
BigInt normalize(int newSign) {
for (int a = s.size() - 1; a > 0 && s[a] == '0'; a--) {
s.erase(s.begin() + a);
}
sign = (s.size() == 1 && s[0] == '0' ? 1 : newSign);
return *this;
}
void operator=(std::string x) {
int newSign = (x[0] == '-' ? -1 : 1);
s = (newSign == -1 ? x.substr(1) : x);
std::reverse(s.begin(), s.end());
this->normalize(newSign);
}
bool operator==(const BigInt& x) const {
return (s == x.s && sign == x.sign);
}
bool operator<(const BigInt& x) const {
if (sign != x.sign) {
return sign < x.sign;
}
if (s.size() != x.s.size()) {
return (sign == 1 ? s.size() < x.s.size() : s.size() > x.s.size());
}
for (int a = s.size() - 1; a >= 0; a--) {
if (s[a] != x.s[a]) {
return (sign == 1 ? s[a] < x.s[a] : s[a] > x.s[a]);
}
}
return false;
}
bool operator<=(const BigInt& x) const {
return (*this < x || *this == x);
}
bool operator>(const BigInt& x) const {
return (!(*this < x) && !(*this == x));
}
bool operator>=(const BigInt& x) const {
return (*this > x || *this == x);
}
BigInt operator+(BigInt x) {
BigInt curr = *this;
if (curr.sign != x.sign) return curr - x.negative();
BigInt res;
for (int a = 0, carry = 0; a < s.size() || a < x.s.size() || carry; a++) {
carry += (a < curr.s.size() ? curr.s[a] - '0' : 0) + (a < x.s.size() ? x.s[a] - '0' : 0);
res.s += (carry % 10 + '0');
carry /= 10;
}
return res.normalize(sign);
}
BigInt operator-(BigInt x) {
BigInt curr = *this;
if (curr.sign != x.sign) return curr + x.negative();
int realSign = curr.sign;
curr.sign = x.sign = 1;
if (curr < x) return ((x - curr).negative()).normalize(-realSign);
BigInt res;
for (int a = 0, borrow = 0; a < s.size(); a++) {
borrow = (curr.s[a] - borrow - (a < x.s.size() ? x.s[a] : '0'));
res.s += (borrow >= 0 ? borrow + '0' : borrow + '0' + 10);
borrow = (borrow >= 0 ? 0 : 1);
}
return res.normalize(realSign);
}
BigInt operator*(BigInt x) {
BigInt res("0");
for (int a = 0, b = s[a] - '0'; a < s.size(); a++, b = s[a] - '0') {
while (b--) res = (res + x);
x.s.insert(x.s.begin(), '0');
}
return res.normalize(sign * x.sign);
}
BigInt operator/(BigInt x) {
if (x.s.size() == 1 && x.s[0] == '0') {
x.s[0] /= (x.s[0] - '0');
}
BigInt temp("0"), res;
for (int a = 0; a < s.size(); a++) res.s += "0";
int newSign = sign * x.sign;
x.sign = 1;
for (int a = s.size() - 1; a >= 0; a--) {
temp.s.insert(temp.s.begin(), '0');
temp = temp + s.substr(a, 1);
while (!(temp < x)) {
temp = temp - x;
res.s[a]++;
}
}
return res.normalize(newSign);
}
BigInt operator%(BigInt x) {
if (x.s.size() == 1 && x.s[0] == '0') {
x.s[0] /= (x.s[0] - '0');
}
BigInt res("0");
x.sign = 1;
for (int a = s.size() - 1; a >= 0; a--) {
res.s.insert(res.s.begin(), '0');
res = res + s.substr(a, 1);
while (!(res < x)) res = res - x;
}
return res.normalize(sign);
}
std::string toString() const {
std::string ret = s;
std::reverse(ret.begin(), ret.end());
return (sign == -1 ? "-" : "") + ret;
}
BigInt toBase10(int base) {
BigInt exp(1), res("0"), BASE(base);
for (int a = 0; a < s.size(); a++) {
int curr = (s[a] < '0' || s[a] > '9' ? (toupper(s[a]) - 'A' + 10) : (s[a] - '0'));
res = res + (exp * BigInt(curr));
exp = exp * BASE;
}
return res.normalize(sign);
}
BigInt toBase10(int base, BigInt mod) {
BigInt exp(1), res("0"), BASE(base);
for (int a = 0; a < s.size(); a++) {
int curr = (s[a] < '0' || s[a] > '9' ? (toupper(s[a]) - 'A' + 10) : (s[a] - '0'));
res = (res + ((exp * BigInt(curr) % mod)) % mod);
exp = ((exp * BASE) % mod);
}
return res.normalize(sign);
}
std::string convertToBase(int base) {
BigInt ZERO(0), BASE(base), x = *this;
std::string modes = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
if (x == ZERO) {
return "0";
}
std::string res = "";
while (x > ZERO) {
BigInt mod = x % BASE;
x = x - mod;
if (x > ZERO) x = x / BASE;
res = modes[stoi(mod.toString())] + res;
}
return res;
}
BigInt toBase(int base) {
return BigInt(this->convertToBase(base));
}
friend std::istream& operator>>(std::istream& is, BigInt& x) {
std::string s;
is >> s;
x = BigInt(s);
return is;
}
friend std::ostream& operator<<(std::ostream& os, const BigInt& x) {
os << x.toString();
return os;
}
};