big_num big_num::operator*(big_num op2)
{
big_num result = 0;
int carry = 0;
result.sign = sign*op2.sign;
//Optimizing the speed because of the loop's attribute
if (number.length() > op2.number.length())
return (op2 * *this);
for ( int i = number.length()-1; i >= 0; i--)
{
big_num temp;
for ( int j = op2.number.length()-1; j >= 0; j--)
{
carry += C2D(number.at(i))*C2D(op2.number.at(j));
temp.number.insert(0,1,D2C(carry%10));
carry /= 10;
}
while (carry != 0)
{
temp.number.insert(0,1,D2C(carry%10));
carry /= 10;
}
temp.number.insert(temp.number.length(), number.length()-i-1, '0');
result = result + temp;
}
return result;
}
/**
@brief convert escape characters(%XX) to ASCII character
*/
void unescape_http_url(
char * url /**< pointer to be converted ( escape characters )*/
)
{
int x, y;
for (x = 0, y = 0; url[y]; ++x, ++y) {
if ((url[x] = url[y]) == '%') {
url[x] = C2D(url[y+1])*0x10+C2D(url[y+2]);
y+=2;
}
}
url[x] = '\0';
}
uint32 ATOI32(
char* str, /**< is a pointer to convert */
uint16 base /**< is a base value (must be in the range 2 - 16) */
)
{
uint32 num = 0;
while (*str !=0)
num = num * base + C2D(*str++);
return num;
}
/**
@brief CONVERT STRING INTO INTEGER
@return a integer number
*/
uint16_t ATOI(
char *str, /**< is a pointer to convert */
uint16_t base /**< is a base value (must be in the range 2 - 16) */
)
{
unsigned int num = 0;
while (*str != 0)
num = num * base + C2D(*str++);
return num;
}
/**
@brief CONVERT STRING INTO INTEGER
@return a integer number
*/
uint16_t ATOI(
uint8_t * str, /**< is a pointer to convert */
uint8_t base /**< is a base value (must be in the range 2 - 16) */
)
{
unsigned int num = 0;
// debug_2013_11_25
// while (*str !=0)
while ((*str !=0) && (*str != 0x20)) // not include the space(0x020)
num = num * base + C2D(*str++);
return num;
}
/**
@brief CONVERT STRING INTO HEX OR DECIMAL
@return success - 1, fail - 0
*/
int ValidATOI(
char* str, /**< is a pointer to string to be converted */
int base, /**< is a base value (must be in the range 2 - 16) */
int* ret /**< is a integer pointer to return */
)
{
int c;
char* tstr = str;
if(str == 0 || *str == '\0') return 0;
while(*tstr != '\0')
{
c = C2D(*tstr);
if( c >= 0 && c < base) tstr++;
else return 0;
}
*ret = ATOI(str,base);
return 1;
}
big_num big_num::operator+(big_num op2)
{
big_num result;
//Error handling
if (this->sign == 0 || op2.sign == 0)
{
result.sign = 0;
return result;
}
int index1, index2;
int carry = 0;
/*CONSIDERING DIFFERENT SITUATION*/
//Compare the two operands' signs
switch (sign * op2.sign) {
case 1: //=>Same:
if (sign == -1) //If both are negative, make the result also negative
result.sign = -1;
break;
case -1: //=>Different:
if (sign == -1) //Change the sum operation to substraction operation
return (op2 - *this*(-1));
else
return (*this - op2*(-1));
break;
default:
break;
}
/*DOING THE ADDITION*/
index1 = number.length() - 1;
index2 = op2.number.length() - 1;
/*Add digit by digit until there's no digit left in one of the two operands*/
for ( ;index1 != -1 && index2 != -1; index1--, index2--)
{
carry += C2D(number.at(index1)) + C2D(op2.number.at(index2));
result.number.insert(0,1,D2C(carry%10));
carry /= 10;
}
/*Carry the digits left in the other operand to the result*/
while (index1 >= 0)
{
if (C2D(number.at(index1))+carry >= 10) {
result.number.insert(0,1,D2C((C2D(number.at(index1))+carry)%10));
carry = 1;
} else {
result.number.insert(0,1,D2C(C2D(number.at(index1)+carry)));
carry = 0;
}
index1--;
}
while (index2 >= 0)
{
if (C2D(op2.number.at(index2))+carry >= 10) {
result.number.insert(0,1,D2C((C2D(op2.number.at(index2))+carry)%10));
carry = 1;
} else {
result.number.insert(0,1,D2C(C2D(op2.number.at(index2)+carry)));
carry = 0;
}
index2--;
}
//Last check the carry var
if (carry != 0)
result.number.insert(0,1,D2C(carry));
return result;
}
