高精度

#define MAXLEN 10010
#define MAXN 9999
#define MAXSIZE 1010
#define DLEN 4
 
class BigNum
{
private:
    int a[MAXLEN];
    int len;
public:
    BigNum() { len = 1; memset(a, 0, sizeof(a)); }
    BigNum(const int);
    BigNum(const char*);
    BigNum(const BigNum&);
    BigNum& operator =(const BigNum &);
    friend istream& operator >>(istream&, BigNum&);
    friend ostream& operator <<(ostream&, BigNum&);
    BigNum operator +(const BigNum&) const;
    BigNum operator -(const BigNum&) const;
    BigNum operator *(const BigNum&) const;
    BigNum operator /(const int&) const;
    BigNum operator ^(const int&) const;
    int operator %(const int&) const;
    bool operator >(const BigNum& T)const;
    bool operator >(const int& t)const;
    void print();
};
 
BigNum::BigNum(const int b)
{
    int c, d = b;
    len = 0;
    memset(a, 0, sizeof(a));
    while (d > MAXN)
    {
        c = d - (d / (MAXN + 1)) * (MAXN + 1);
        d = d / (MAXN + 1);
        a[len++] = c;
    }
    a[len++] = d;
}
 
BigNum::BigNum(const char* s)
{
    int t, k, index, L, i;
    memset(a, 0, sizeof(a));
    L = (int)strlen(s);
    len = L / DLEN;
    if (L % DLEN) len++;
    index = 0;
    for (i = L - 1; i >= 0; i -= DLEN)
    {
        t = 0;
        k = i - DLEN + 1;
        if (k < 0) k = 0;
        for (int j = k; j <= i; j++)
            t = t * 10 + s[j] - '0';
        a[index++] = t;
    }
}
 
BigNum::BigNum(const BigNum& T) : len(T.len)
{
    int i;
    memset(a, 0, sizeof(a));
    for (i = 0; i < len; i++) a[i] = T.a[i];
}
 
BigNum& BigNum::operator =(const BigNum& n)
{
    int i;
    len = n.len;
    memset(a, 0, sizeof(a));
    for (i = 0; i < len; i++) a[i] = n.a[i];
    return *this;
}
 
istream& operator >>(istream& in, BigNum& b)
{
    char ch[MAXSIZE * 4];
    int i = -1;
    in >> ch;
    int L = (int)strlen(ch);
    int count = 0, sum = 0;
    for (i = L - 1; i >= 0;)
    {
        sum = 0;
        int t = 1;
        for (int j = 0; j < 4 && i >= 0; j++, i--, t *= 10)
            sum += (ch[i] - '0') * t;
        b.a[count] = sum;
        count++;
    }
    b.len = count++;
    return in;
}
 
ostream& operator <<(ostream& out, BigNum& b)
{
    int i;
    cout << b.a[b.len - 1];
    for (i = b.len - 2; i >= 0; i--)
        printf("%04d", b.a[i]);
    return out;
}
    
BigNum BigNum::operator +(const BigNum& T) const
{
    BigNum t(*this);
    int i, big;
    big = T.len > len ? T.len : len;
    for (i = 0; i < big; i++)
    {
        t.a[i] += T.a[i];
        if (t.a[i] > MAXN)
        {
            t.a[i + 1]++;
            t.a[i] -= MAXN + 1;
        }
    }
    if (t.a[big] != 0) t.len = big + 1;
    else t.len = big;
    return t;
}
 
BigNum BigNum::operator -(const BigNum& T) const
{
    int i, j, big;
    bool flag;
    BigNum t1, t2;
    if (*this > T)
    {
        t1 = *this;
        t2 = T;
        flag = 0;
    }
    else
    {
        t1 = T;
        t2 = *this;
        flag = 1;
    }
    big = t1.len;
    for (i = 0; i < big; i++)
    {
        if (t1.a[i] < t2.a[i])
        {
            j = i + 1;
            while (t1.a[j] == 0) j++;
            t1.a[j--]--;
            while (j > i) t1.a[j--] += MAXN;
            t1.a[i] += MAXN + 1 - t2.a[i];
        }
        else t1.a[i] -= t2.a[i];
    }
    t1.len = big;
    while (t1.a[t1.len - 1] == 0 && t1.len > 1)
    {
        t1.len--;
        big--;
    }
    if (flag) t1.a[big - 1] = 0 - t1.a[big - 1];
    return t1;
}
 
BigNum BigNum::operator *(const BigNum& T)const
{
    BigNum ret;
    int i, j = 0, up;
    int temp, temp1;
    for (i = 0; i < len; i++)
    {
        up = 0;
        for (j = 0; j < T.len; j++)
        {
            temp = a[i] * T.a[j] + ret.a[i + j] + up;
            if (temp > MAXN)
            {
                temp1 = temp - temp / (MAXN + 1) * (MAXN + 1);
                up = temp / (MAXN + 1);
                ret.a[i + j] = temp1;
            }
            else
            {
                up = 0;
                ret.a[i + j] = temp;
            }
        }
        if (up != 0) ret.a[i + j] = up;
    }
    ret.len = i + j;
    while (ret.a[ret.len - 1] == 0 && ret.len > 1) ret.len--;
    return ret;
}
 
BigNum BigNum::operator /(const int& b)const
{
    BigNum ret;
    int i, down = 0;
    for (i = len - 1; i >= 0; i--)
    {
        ret.a[i] = (a[i] + down * (MAXN + 1)) / b;
        down = a[i] + down * (MAXN + 1) - ret.a[i] * b;
    }
    ret.len = len;
    while (ret.a[ret.len - 1] == 0 && ret.len > 1) ret.len--;
    return ret;
}
 
int BigNum::operator %(const int& b) const
{
    int i, d = 0;
    for (i = len - 1; i >= 0; i--)
        d = ((d * (MAXN + 1)) % b + a[i]) % b;
    return d;
}
 
BigNum BigNum::operator ^(const int& n) const
{
    BigNum t, ret(1);
    int i;
    if (n < 0) exit(-1);
    if (n == 0) return 1;
    if (n == 1) return *this;
    int m = n;
    while (m > 1)
    {
        t = *this;
        for (i = 1; (i << 1) <= m; i <<= 1) t = t * t;
        m -= i;
        ret = ret * t;
        if (m == 1) ret = ret * (*this);
    }
    return ret;
}
 
bool BigNum::operator >(const BigNum& T) const
{
    int ln;
    if (len > T.len) return true;
    else if (len == T.len)
    {
        ln = len - 1;
        while (a[ln] == T.a[ln] && ln >= 0) ln--;
        if (ln >= 0 && a[ln] > T.a[ln]) return true;
        else return false;
    }
    else return false;
}
 
bool BigNum::operator >(const int& t) const
{
    BigNum b(t);
    return *this > b;
}
 
void BigNum::print()
{
    int i;
    printf("%d", a[len - 1]);
    for (i = len - 2; i >= 0; i--)
        printf("%04d", a[i]);
    printf("\n");
}