Created
June 28, 2020 13:30
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Decimal to precise float precision cut
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#include <stdlib.h> | |
#include <stdio.h> | |
#include <iostream> | |
#include <sstream> | |
#include <limits> | |
using namespace std; | |
int main() { | |
char buf [100]; | |
float f1 = (float)0.000000196565025589734432287514209747314453125; | |
float f2; | |
sprintf( buf, "%.*e", FLT_DECIMAL_DIG, f1 ); | |
printf("%s\n", buf); | |
sscanf(buf, "%f", &f2); | |
printf("%g %g %g %d\n", f1,f2, f1-f2, f1==f2); | |
stringstream ss; | |
ss.precision(std::numeric_limits<float>::max_digits10+2); | |
cout.precision(std::numeric_limits<float>::max_digits10+2); | |
ss << f1; | |
ss >> f2; | |
cout << f1 << endl << f2 << endl << ss.str() << endl << (f1 == f2) << endl; | |
return 0; | |
} |
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