Question

How to count the numbers with even number of digits in a vector with C++

Answer 1

#include <iostream>
#include <vector>
#include <cmath>
 
int count_even_numbers(std::vector <int> &vec) {
    int result = 0;
 
    for (int &n : vec) {
        int total_digits = (log10(n) + 1);
         
        if (total_digits % 2 == 0)
            result++;
    }
             
    return result;
}
 
int main()
{
    std::vector <int> v = {564, 90, 7, 1248, 47325, 834921, 1234567};
     
    std::cout << count_even_numbers(v);
}
 
 
 
 
/*
run:
 
3
 
*/

 

70+ SQL courses for beginners and professionals