标签：大数四则运算 小项目
代码如下：
#pragma once
#include<iostream>
#include<assert.h>
#include<string>
using namespace std;
#define UN_INIT 0XCCCCCCCCCCCCCCCC;
#define MAX 0x7FFFFFFFFFFFFFFF
#define MIN 0X8000000000000000
typedef long long INT64;
class BigData
{
public:
BigData(INT64 value=0xCCCCCCCCCCCCCCCC) :_value(value)
{
ToString();
};
BigData(const char *p);
BigData operator+(BigData & bigdata);
BigData operator-(BigData & bigdata);
BigData operator*(BigData & bigdata);
BigData operator/(BigData & bigdata);
friend ostream& operator <<(ostream & _cout, const BigData& bigdata);
private:
bool IsOver64()const
{
string tmp("+9223372036854775807");
if (_StrData[0] == ‘-‘)
{
tmp = "-9223372036854775808";
}
if (_StrData.size() < tmp.size())
return true;
else if (_StrData.size() == tmp.size() && _StrData <= tmp)
return true;
return false;
}
string Add(string left, string right);
string Sub(string left, string right);
string Mul(string left, string right);
string Div(string left, string right);
private:
bool IsLeftBig(const char *left, int lSize, const char *right, int rSize);
char SubLoop( char *left, int lSize, const char *right, int rSize);
void ToString();
INT64 _value;
string _StrData;
};
BigData::BigData(const char *pData)
{
//1212312 asdasd 1221312qwe 0000qweqwe
if (pData == NULL)
return;
char *p =(char *) pData;
char _Symble = pData[0];
if (_Symble == ‘+‘||_Symble == ‘-‘)
{
p++;
}
else if (_Symble >= ‘0‘ && _Symble <= ‘9‘)
{
_Symble = ‘+‘;
}
else _Symble = ‘-‘;
while (*p == ‘0‘)
{
p++;
}
_StrData.resize(strlen(pData) + 1);
_StrData[0] = _Symble;
int count = 1;
_value = 0;
while (*p>=‘0‘&&*p<=‘9‘)
{
_value = _value*10 + (*p-‘0‘);
_StrData[count++] = *p;
p++;
}
if (_Symble == ‘-‘)
_value = 0 - _value;
_StrData.resize(count);
};
ostream& operator<<(ostream & _cout, const BigData& bigdata)
{
//是否溢出判断
//
if (bigdata.IsOver64())
{
_cout << bigdata._value << endl;
}
else _cout << bigdata._StrData << endl;
return _cout;
}
void BigData::ToString()
{
INT64 temp=_value;//1111111111111111
if (_value > 0)
_StrData.append(1, ‘+‘);
else
{
_StrData.append(1, ‘-‘);
}
if (_value < 0)
temp = 0 - _value;
while (temp)
{
char cStr = temp % 10 + ‘0‘;
_StrData.append(1, cStr);
temp /= 10;
}
int left = 1; int right = _StrData.size()-1;
while (left < right)
{
swap(_StrData[left], _StrData[right]);
++left;
--right;
}
}
bool BigData::IsLeftBig(const char *left, int lSize, const char *right, int rSize)
{
if (lSize > rSize || lSize == rSize&&strcmp(left, right) >=0)
{
return true;
}
return false;
}
char BigData::SubLoop( char *left, int lSize, const char *right, int rSize)
{
char Cret = ‘0‘;
while (true)
{
if (!IsLeftBig(left, lSize, right, rSize))//如果左边小
{
break;
}
else//循环相减法
{
int lsize = lSize - 1;
int rsize = rSize - 1;
while (lsize>=0&&rsize>=0)
{
char ret = left[lsize] - ‘0‘;
ret -= right[rsize] - ‘0‘;
if (ret < 0)
{
left[lsize-1] -= 1;
ret += 10;
}
left[lsize] = ret + ‘0‘;
lsize--;
rsize--;
}
while (*left == ‘0‘&&lSize>0)
{
left++;
lSize--;
}
Cret++;
}
}
return Cret;
}
BigData BigData::operator +(BigData & bigdata)
{
if (IsOver64() && bigdata.IsOver64())//都不溢出
{
if (_StrData[0] != bigdata._StrData[0])
{
return BigData(_value + bigdata._value);
}
INT64 tmp = MIN - _value;
if ((_value > 0 && (MAX - _value >= bigdata._value)) || (_value < 0 && (tmp <= bigdata._value)))
{
return BigData(_value + bigdata._value);
}
}
//至少有一个溢出
//结果溢出
if (_StrData[0] == bigdata._StrData[0])
return BigData(Add(_StrData, bigdata._StrData).c_str());
else return BigData(Sub(_StrData, bigdata._StrData).c_str());//符号位相反 取反。
}
string BigData::Add(string left, string right)//
{
int iLeft = left.size();
int iRight = right.size();
string ret;
ret.append(1, left[0]);
if (left[0] != right[0])
{
if (left[0] == ‘-‘)
ret[0] = ‘+‘;
if (right[0] == ‘+‘)
ret[0] = ‘-‘;
}
if (iLeft < iRight)
{
swap(left, right);
swap(iLeft, iRight);
}
ret.resize(iLeft + 1);
char step = 0;
for (int index = 1; index < iLeft; ++index)
{
char Cstr = left[iLeft - index] - ‘0‘ + step;
if (index < iRight)
{
Cstr += (right[iRight - index] - ‘0‘);
}
ret[iLeft - index + 1] = Cstr % 10 + ‘0‘;
step = Cstr / 10;
}
ret[1] = step + ‘0‘;
return ret;
}
BigData BigData::operator -(BigData & bigdata)
{
if (IsOver64() && bigdata.IsOver64())//两个不溢出
{
if (_StrData[0] == bigdata._StrData[0])
{
return BigData(_value - bigdata._value);
}
else
{//10 -1 11 -11 1 -12
if ((_value>0 || (_value<0) && MIN + bigdata._value <= _value))
return BigData(_value - bigdata._value);
}
}
if (_StrData[0] != bigdata._StrData[0])
{
//bigdata._StrData[0] = _StrData[0];
return BigData(Add(_StrData, bigdata._StrData).c_str());
}
else
{
return BigData(Sub(_StrData, bigdata._StrData).c_str());//符号位相同
}
}
string BigData::Sub(string left, string right)
{
//if (left[0]==right[])
int iLeft = left.size();
int iRight = right.size();
string ret;
char symble = left[0];
if (iLeft < iRight || (iLeft == iRight&&left<right))//左边的xiao
{
swap(left, right);
swap(iLeft, iRight);
if (symble == ‘+‘)
symble = ‘-‘;
else
{
symble = ‘+‘;
}
}
ret.resize(iLeft);
ret[0] = symble;
char step = 0;
for (int index = 1; index < iLeft; ++index)
{
char Cstr = left[iLeft - index] - ‘0‘;
if (index < iRight)
{
Cstr -= (right[iRight - index] - ‘0‘);
}
if (Cstr < 0)
{
left[iLeft - index - 1] -= 1;
Cstr += 10;
}
ret[iLeft - index] = Cstr + ‘0‘;
}
return ret;
}
BigData BigData::operator *(BigData & bigdata)
{
//
if (IsOver64() && bigdata.IsOver64())
{
if (_StrData[0] == bigdata._StrData[0])//-10 -2 5
{
if ((_value > 0 && MAX / _value >= bigdata._value) || (_value < 0 && (MAX / _value <= bigdata._value)))
return BigData(_value*bigdata._value);
}
else
{
if ((_value > 0 && MIN / _value >= bigdata._value) || (_value < 0 && (MIN / _value >= bigdata._value)))
return BigData(_value*bigdata._value);
}
}
return BigData(Mul(_StrData, bigdata._StrData).c_str());
}
string BigData::Mul(string left, string right)
{
char symbol = ‘+‘;
if (left[0] != right[0])
symbol = ‘-‘;
int iLeft = left.size();
int iRight = right.size();
if (iLeft > iRight)
{
swap(left, right);
swap(iLeft, iRight);
}
string ret;
//ret.resize(iLeft + iRight - 1);
ret.assign(iLeft + iRight -1, ‘0‘);
ret[0] = symbol;
int ioffset = 0;
int rlen = ret.size();
for (int index = 1; index < iLeft; ++index)
{
char Cleft = left[iLeft - index] - ‘0‘;
char step = 0;
if (Cleft == ‘0‘)
{
++ioffset;
continue;
}
for (int index = 1; index < iRight; ++index)
{
char Cstr = Cleft*(right[iRight - index] - ‘0‘) + step;//取到字符
Cstr += (ret[rlen - index - ioffset] - ‘0‘);//累加
ret[rlen - index - ioffset] = (((Cstr) % 10)+‘0‘ );
step = Cstr / 10;
}
ret[rlen - iRight - ioffset] += step;
ioffset++;
}
return ret;
}
BigData BigData::operator /(BigData & bigdata)
{
assert(bigdata._value != 0);
if (IsOver64() && bigdata.IsOver64())//不溢出
{
return BigData(_value / bigdata._value);
}
if (_StrData.size() < bigdata._StrData.size() || (_StrData.size() == bigdata._StrData.size()&&strcmp(_StrData.c_str() + 1, bigdata._StrData.c_str() + 1) < 0))
{
return BigData(INT64(0));
}
if (bigdata._StrData == "+1" || bigdata._StrData == "-1")
{
if (_StrData[0] != bigdata._StrData[0])
{
_StrData[0] = ‘-‘;
}
else _StrData[0] = ‘+‘;
return *this;
}
if (strcmp(_StrData.c_str() + 1, bigdata._StrData.c_str() + 1) == 0)
{
if (_StrData[0] != bigdata._StrData[0])
{
return BigData(INT64(1));
}
else return BigData(INT64(-1));
}
return BigData(Div(_StrData, bigdata._StrData).c_str());
}
string BigData::Div(string left, string right)
{
string ret;
ret.append(1, ‘+‘);
if (left[0] != right[0])
{
ret[0] = ‘-‘;
}
int LSize = left.size() - 1;
int Rsize= right.size() - 1;
char *Left = (char *)left.c_str() + 1;
char *Right = (char *)right.c_str() + 1;
int datalen = Rsize;
for (int index = 0; index < LSize;)
{
if (!IsLeftBig(Left, datalen, Right, Rsize))//左边小于右边
{
ret.append(1, ‘0‘);
datalen++;
if (datalen + index>LSize)
break;
}
else
{
ret.append(1, SubLoop(Left, datalen, Right, Rsize));
while (*Left == ‘0‘&&datalen > 0)
{
Left++;
index++;
datalen--;
}
datalen++;
if (index + datalen > LSize)
break;
}
}
return ret;
}
测试用例如下：
oid testAdd()
{
BigData b1("-45353" );
BigData b2("37353753" );
BigData b3("-9223372036854775808" );
BigData b4("9223372036854775800" );
BigData b5("-9223372036854775810" );
BigData b6("9223372036854775900" );
//1、都在INT64范围内<运算后在范围内，运算后不在范围内>（再进行构造可以解决）
cout << (b1 + b1) << endl;
cout << (b2 + b2) << endl;
cout << (b1 + b2) << endl;
cout << (b1 + b4) << endl;
cout << b3 << endl;
cout << (b1 + b3) << endl;
cout << (b2 + b4) << endl;
//2、都不在INT64范围内<运算后在范围内，运算后不在范围内>
cout << (b2 + b5) << endl;
cout << (b1 + b6) << endl;
cout << (b6 + b1) << endl;
//3、一个在一个不在<运算后在范围内，运算后不在范围内>
cout << endl;
cout << endl;
cout << endl;
cout << endl;
}
void testSub()
{
BigData b1("-45353" );
BigData b2("37353753" );
BigData b3("-9223372036854775808" );
BigData b4("9223372036854775800" );
BigData b5("-9223372036854775810" );
BigData b6("9223372036854775900" );
//1、都在INT64范围内<运算后在范围内，运算后不在范围内>（再进行构造可以解决）
cout << (b1 - b2) << endl;
cout << (b2 - b1) << endl;
cout << (b3 - b1) << endl;
cout << (b1 - b4) << endl;
cout << (b3 - b2) << endl;
cout << (b4 - b1) << endl;
cout << (b1 - b3) << endl;
cout << (b2 - b4) << endl;
cout << endl;
//2、一个在一个不在<运算后在范围内，运算后不在范围内>
cout << (b5 - b1) << endl;
cout << (b1 - b5) << endl;
cout << endl;
cout << (b6 - b2) << endl;
cout << (b2 - b6) << endl;
cout << endl;
cout << (b6 - b5) << endl;
cout << (b5 - b6) << endl;
cout << (b2 - b5) << endl;
cout << (b1 - b6) << endl;
cout << (b6 - b1) << endl;
}
void test()
{
BigData c1("999" );
BigData c2("222222222222222222222222222" );
cout<< c1*c2<<endl;
}
void testMul()
{
BigData b1("-45353" );
BigData b2("37353753" );
BigData b3("-9223372036854775808" );
BigData b4("9223372036854775800" );
BigData b5("-9223372036854775810" );
BigData b6("9223372036854775900" );
//1、都在INT64范围内<运算后在范围内，运算后不在范围内>（再进行构造可以解决）
cout << ( BigData("999" ) * BigData( "22222222222222222222222222222" )) << endl;
cout << (b2 * b1) << endl;
cout << (b1 * b2) << endl;
cout << (b1 * BigData("0" )) << endl;
cout << ( BigData("0" ) * b2) << endl;
cout << endl;
cout << (b3 * b1) << endl;
cout << (b1 * b3) << endl;
cout << (b1 * b4) << endl; // 错误
cout << (b4 * b1) << endl; // 正确
cout << (b3 * b2) << endl; // 错误
cout << (b2 * b4) << endl; // 正确
cout << endl;
//2、一个在一个不在<运算后在范围内，运算后不在范围内>
cout << ( BigData("0" ) * b6) << endl;
cout << (b5 * BigData("0" )) << endl;
cout << (b5 * b1) << endl;
cout << (b1* b5) << endl;
cout << endl;
cout << (b6 * b2) << endl;
cout << (b2 * b6) << endl;
cout << endl;
cout << (b6 * b5) << endl;
cout << (b5 * b6) << endl;
cout << (b2 * b5) << endl;
cout << endl;
cout << (b1 * b6) << endl;
cout << (b6 * b1) << endl;
}
void testDiv()
{
BigData b1("-45353" );
BigData b2("37353753" );
BigData b3("-9223372036854775808" );
BigData b4("9223372036854775800" );
BigData b5("-9223372036854775810" );
BigData b6("9223372036854775900" );
//1、排除除数为0
//cout << (b1 / BigData(0)) << endl;
//2、在范围内
cout << (b1 / b2) << endl;
cout << (b2 / b1) << endl;
//3、不在范围内<左（被除数）比右（除数）小为0，左比右大>
cout << (b2 / b5) << endl;
cout << (b2 / b6) << endl;
cout << (b5 / b2) << endl;
cout << (b6 / b2) << endl;
cout << (b6 / b1) << endl;
cout << (b5 / b1) << endl;
BigData b7("-1231123203367738338252" );
cout << b7 / b1 << endl;
}
int main()
{
//testMul();
//testAdd();
//testSub();
//testMul();
//test();
//BigData(10);
testDiv();
//BigData b1("2222222222222222222222222");
//BigData b2("33");
//cout << b1 / b2 << endl;
return 0;
}
标签：大数四则运算 小项目
原文地址：http://10955910.blog.51cto.com/10945910/1760866
