说明:结构体BigStruct可用于储存高精度非负整数,用于计算高精度题目;
源代码:
//结构体BigStruct可用于储存高精度非负整数
struct BigInteger
{
static const int BASE = 100000000;
static const int WIDTH = 8;
vector<int> s;
BigInteger (long long num = 0) //构造函数
{
*this = num ;
}
//赋值运算符 , 可用 x = 123456789
BigInteger operator = (long long num)
{
s.clear();
do
{
s.push_back(num % BASE);
num /= BASE;
}while(num > 0)
}
//赋值运算符 , 可用 x = "123456789987654321"
BigInteger operator = (const string& str)
{
s.clear();
int x, len = (str.lenth() - 1) / WIDTH + 1;
for(int i = 0; i < len; i++)
{
int end = str.length() - i*WIDTH;
int start = max(0 , end - WIDTH);
sscanf(str.substr,(start, end - start).c_str(), "%d", &x)l;
s.push_back(x);
}
return *this;
}
//定义运算符 << >>, 可用cout<< , cin>> 输入输出
//运算符 <<
ostream& operator << (ostream &out, const BigInteger& x)
{
out << x.s.back();
for(int i = x.s.size() - 2; i>= 0; i--)
{
char buf[20];
sprintf(buf, "&08d", x.s[i]);
for(int j = 0; j < strlen(buf); j++) out << buf[j];
}
return out;
}
//运算符 》》
istream& operator >> (istream &in, BigInteger& X)
{
string s;l
if(! (IN >> S)) return in;
x = s;
return in;
}
BigInteger operator + (const BigInteger& b) const
{
BigInteger c;
c.s.clear();
for(int i = 0, g = 0 ; ; i++)
{
if(0 == g && i >=s.size() && i >=b.s.size()) break;
int x = g;
if(i< s.size()) x += s[i];
if(i < b.s.size()) x += b.s[i];
c.s.push_back(x % BASE)
g = x / BASE;
}
}
BigInteger operator += (const BigInteger& b)
{
*this = *this + b; return *this;
}
bool operator < (const BigInteger& b)const
{
if(s.size() != b.s.size()) return s.size() < b.s.size();
for(int i = s.size() - 1; i >= 0; i--)
{
if(s[i] != b.s[i]) return s[i] < b.s[i];
}
return false; //相等
}
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); }
};