### 2.学校OJ加减乘除取模均AC

```//BigInt V2.1
//By KunSoft

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <string>
#include <cmath>
#include <deque>
#include <iterator>
#include <algorithm>
using namespace std;
typedef long long LLT;

class BigInt
{
public:
BigInt():num(), negative(false){}
BigInt(const LLT);
BigInt(const char*);
BigInt(const string);
BigInt(const BigInt & x);
BigInt & operator = (const BigInt &);
friend istream & operator >> (istream &, BigInt &);
friend ostream & operator << (ostream &, BigInt);
const BigInt operator + (const BigInt &) const;
const BigInt operator - (const BigInt &) const;
const BigInt operator * (const BigInt &) const;
const BigInt operator / (const LLT &) const;
const LLT operator % (const LLT &) const;
bool operator > (const BigInt &) const;
bool operator < (const BigInt &) const;
bool operator == (const BigInt &) const;
bool operator >= (const BigInt &) const;
bool operator <= (const BigInt &) const;
friend const BigInt abs(const BigInt &);
const BigInt operator - () const;
private:
deque<int> num;
bool negative;
};

BigInt::BigInt(const LLT x){
LLT t = abs(x);
negative = x >= 0 ? false : true;
while (t > 0){
num.push_back(t % 10);
t /= 10;
}
}
BigInt::BigInt(const char* str){
unsigned i = str[0] == '-' ? 1 : 0;
this->negative = (str[0] == '-' ? true : false);
for (; i < strlen(str); ++i) num.push_back(str[i] - '0');
}
BigInt::BigInt(const string str){
unsigned i = str[0] == '-' ? 1 : 0;
this->negative = (str[0] == '-' ? true : false);
for (; i < str.size(); ++i) num.push_back(str[i] - '0');
}
BigInt::BigInt(const BigInt &x):num(x.num), negative(x.negative){}
BigInt & BigInt::operator = (const BigInt &x){
negative = x.negative;
num = x.num;
return (*this);
}
istream & operator >> (istream &is, BigInt & x){
string str; is >> str;
x = str;
return is;
}
ostream & operator << (ostream &os, BigInt x){
if (x.negative) os << '-';
for (unsigned i = 0; i != x.num.size(); ++i)
os << x.num[i];
return os;
}
bool BigInt::operator > (const BigInt & rhs) const {
BigInt x = (*this), y = rhs;
if (!x.negative && y.negative) return true;
if (x.negative && !y.negative) return false;
if (x.negative && y.negative) swap(x, y);
if (x.num.size() > y.num.size()) return true;
if (x.num.size() < y.num.size()) return false;
for (unsigned i = 0; i != x.num.size(); ++i) {
if (x.num[i] > y.num[i]) return true;
if (x.num[i] < y.num[i]) return false;
}
return false;
}
bool BigInt::operator < (const BigInt & rhs) const {
return rhs < *this;
}
bool BigInt::operator == (const BigInt & rhs) const {
return negative == rhs.negative && num == rhs.num;
}
bool BigInt::operator >= (const BigInt & rhs) const {
return *this > rhs || *this == rhs;
}
bool BigInt::operator <= (const BigInt & rhs) const {
return rhs >= *this;
}
const BigInt abs(const BigInt & rhs){
BigInt res;
res.negative = false;
res.num = rhs.num;
return res;
}
const BigInt BigInt::operator - () const {
BigInt ret = *this; ret.negative = !ret.negative;
return ret;
}
const BigInt BigInt::operator + (const BigInt & y) const {
if (!this->negative && y.negative) return *this - abs(y);
if (this->negative && !y.negative) return y - abs(*this);
if (this->negative && y.negative) return -(abs(*this) + abs(y));
BigInt x = *this, res;
int temp = 0;
for (int i = x.num.size() - 1, j = y.num.size() - 1; i >= 0 || j >= 0; --i, --j) {
int a = i < 0 ? 0 : x.num[i];
int b = j < 0 ? 0 : y.num[j];
res.num.push_front((a + b + temp) % 10);
temp = (a + b + temp) / 10;
}
if (temp != 0) res.num.push_front(temp);
return res;
}
const BigInt BigInt::operator * (const BigInt & y) const {
deque<int> a, b, res;
copy(this->num.begin(), this->num.end(), front_inserter(a));
copy(y.num.begin(), y.num.end(), front_inserter(b));
res.resize(a.size() + b.size() + 5);
for (unsigned i = 0; i < a.size(); ++i) for (unsigned j = 0; j < b.size(); ++j)
res[i + j] += a[i] * b[j];
for (unsigned i = 0; i < res.size() - 1; ++i){
res[i + 1] += res[i] / 10;
res[i] %= 10;
}
while (res.size() >= 2 && res.back() == 0)
res.pop_back();
reverse(res.begin(), res.end());
BigInt ret; ret.negative = this->negative ^ y.negative; ret.num = res;
return ret;
}
const BigInt BigInt::operator - (const BigInt & y) const {
if (!this->negative && y.negative) return *this + abs(y);
if (this->negative && !y.negative) return -(abs(*this) + y);
if (this->negative && y.negative) return abs(y) - abs(*this);
deque<int> a, b, res; BigInt ret;
copy(this->num.begin(), this->num.end(), front_inserter(a));
copy(y.num.begin(), y.num.end(), front_inserter(b));
if (y > *this) swap(a, b), ret.negative = true;
res.resize(max(a.size(), b.size()) + 5);
for (unsigned i = 0, j = 0; i < a.size() || j < b.size(); ++i, ++j){
int m = i < a.size() ? a[i] : 0;
int n = j < b.size() ? b[j] : 0;
res[i] = m - n;
}
for (unsigned i = 0; i < res.size() - 1; ++i) if (res[i] < 0) {
res[i] += 10;
--res[i + 1];
}
while (res.size() >= 2 && res.back() == 0)
res.pop_back();
reverse(res.begin(), res.end()); ret.num = res;
return ret;
}
const BigInt BigInt::operator / (const LLT & rhs) const {
LLT temp = 0;
BigInt x = (*this), res;
res.negative = this->negative ^ (rhs < 0 ? 1 : 0);
int y = abs(rhs);
for (unsigned i = 0; i < x.num.size(); ++i){
temp = temp * 10 + x.num[i];
res.num.push_back((int)(temp / y));
temp %= y;
}
while (res.num.size() >= 2 && res.num.front() == 0)
res.num.pop_front();
return res;
}
const LLT BigInt::operator % (const LLT & y) const {
LLT res = 0;
for (unsigned i = 0; i < this->num.size(); ++i)
res = (res * 10 + this->num[i]) % y;
return res;
}

int main()
{
BigInt a; LLT b;
while (cin >> a >> b)
cout << a / b << endl;
return  0;
}
```