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/**
*
* double -> string
*
*/
char num2char(unsigned int num)
{
switch(num)
{
case 0:
return '0';
case 1:
return '1';
case 2:
return '2';
case 3:
return '3';
case 4:
return '4';
case 5:
return '5';
case 6:
return '6';
case 7:
return '7';
case 8:
return '8';
case 9:
return '9';
}
//return '\0';
return '-';
}
std::string double2str(long double D)
{
int sign = (D > 0) ? 1 : (D*=-1.0, -1);
unsigned long long int Ceil = D;
// if D is ceil
if(Ceil == D)
{
return std::to_string( (long long)(D*sign) );
}
// size of result buffer
const int bs = 32;
// size of temporary buffer
const int pw = 16;
// Temporary buffer
char buf[pw];
// Result buffer
char rez[bs];
int i, size = 0;
// set sign
if(sign < 0) rez[size++] = '-';
// set ceil
std::string sceil = std::to_string(Ceil);
const char * bceil = sceil.c_str();
int sceillen = sceil.size();
for(i = 0; i < sceillen; i++)
{
rez[size++] = bceil[i];
}
// set point
rez[size++] = '.';
unsigned long long int I = D * 10000000000000000; // D * 10**pw
// .14159265359 -> 14159265359000000
I -= Ceil * 10000000000000000;
// Remove the tail of zeros
// 14159265359000000 -> 14159265359
while(0 == I % 10) I /= 10;
int ind = 0;
while(I > 0)
{
buf[ind++] = num2char(I%10);
I = (I - I%10) / 10;
}
// set fraction part
for(i = 0; i < ind; i++)
{
rez[size] = buf[ind-i-1];
size++;
}
return std::string(rez, size);
//rez[size] = '\0';
}
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