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(C++) std::count_if

 

std::count_if is an STL algorithm for counting elements in a container matching a certain predicate. For counting without a predicate use std::count.

 

 

 

 

 

Example: CountNonZeroes

 

#include <algorithm>
#include <vector>

//From http://www.richelbilderbeek.nl/CppCountNonZeroes.htm
int CountNonZeroes(const std::vector<double>& v)
{
 return std::count_if(
    v.begin(),
    v.end(),
    std::bind2nd(std::not_equal_to<double>(),0.0));
}

 

 

 

 

 

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