parse collection of single integers into floats - c++

Question

So i slurped in a file with numbers in it like: 39.00 into a vector<std::string> and now I need to convert groups of numbers that look like 3 9 0 0 back into the form 39.00
heres a small sample.
3 4 5 0 1 2 5 0 3 4 0 0 3 4 9 0 7 0 0 0 8 0 0 0 9 0 0 0 6 5 0 0 3 9 3 2 1 1 2 0 0 0 2 5 0 0 3 0 9 0 4 0 0 0 5 5 5 0 2 0 0 0 2 5 0 0 3 0 9 0 4 0 0 0 5 5 5 0 2 2 3 0 0 0 2 4 0 0 4 5 0 0 6 7 0 0 6 5 5 0 5 6 9 0 8 7 0 0 4 3 5 0 5 6 9 8 5 5 4 0 3 3 6 2 0 0 3 4 5 0 1 2 5 0 3 4 0 0 3 4 9 0 7 0 0 0 8 0 0 0 9 0 0 0 6 5 0 0 3 9 0 3 2 1 1 2 0 0 0 2 5 0 0 3 0 9 0 4 0 0 0 5 5 5 0 2 0 0 0 2 5 0 0 3 0 9 0 4 0 0 0 5 5 5 0 2 2 3 0 0 0 2 4 0 0 4 5 0 0 6 7 0 0 6 5 5 0 5 6 9 0 8 7 0 0 4 3 5 0 5 6 9 8 5 5 4 0 3 3 6 2 0 0 3 4 5 0 1 2 5 0 3 4 0 0 3 4 9 0 7 0 0 0 8 0 0 0 9 0 0 0 6 5 0 0 3 9 0 0
transformed into 34.50 12.50 34.00....
My goal is to eventually find the average of all the floats.
Of course if there is a way to slurp a file while keeping formatting only using the standard library that would be cool too.
#include <iostream>
#include <string>
#include <fstream>
#include <streambuf>
#include <regex>
#include <vector>
#include <math.h>
void tableWriter(std::string);
float employeeAverage(std::string);
float employeeTotal(std::string);
float totalAverage(std::string);
void totalPayroll(std::string, std::vector<std::string>);
std::string getEmployeeName(std::string, std::string[]);
int main(int argc, const char * argv[]) {
try {
std::vector<std::string> regexContainer;
std::ifstream t("TheSales.txt");
std::string theSales;
t.seekg(0, std::ios::end);
theSales.reserve(t.tellg());
t.seekg(0, std::ios::beg);
theSales.assign((std::istreambuf_iterator<char>(t)),
std::istreambuf_iterator<char>());
//std::cout << theSales << std::endl;
totalPayroll(theSales, regexContainer);
std::cout << std::endl << regexContainer.empty() << std::endl;
return 0;
} catch (int w) {
std::cout << "Could not open file. Exiting Now." << std::endl; return 0;
}
}
void tableWriter(std::string){}
float employeeAverage(std::string){return 0.0;}
float employeeTotal(std::string){return 0.0;}
float totalAverage(std::string){return 0.0;}
void totalPayroll(std::string theSales, std::vector<std::string> regexContainer) {
std::string matches;
std::regex pattern ("\\d");
const std::sregex_token_iterator end;
for (std::sregex_token_iterator i(theSales.cbegin(), theSales.cend(), pattern);
i != end;
++i)
{
regexContainer.push_back(*i);
for (std::vector<std::string>::const_iterator i = regexContainer.begin(); i != regexContainer.end(); ++i)
std::cout << *i << ' ';
}
}
this is the data:
2.40 5.30 6.30 65.34 65.34
3.40 7.80 3.20 65.34 65.34
3.40 5.20 8.20 23.54 12.34
2.42 5.30 6.30 5.00 65.34
3.44 7.80 3.20 34.55 65.34
3.45 5.20 8.20 65.34 65.34

Answer 1

Functions such as fscanf are able to read from your file and return a correctly formed float number. This should be more efficient than trying to reconstruct them from a stream of char...