#include <cctype>
#include <iostream>
#include <map>
#include <sstream>
#include <string>
#include <vector>

int main(int argc, char** argv)
{
    std::vector<int> nums;
    nums.push_back(5789);
    nums.push_back(-9876);
    nums.push_back(12345);
    nums.push_back(56789);
    nums.push_back(56788);
    nums.push_back(-1111);
    
    std::map<char, int> digit_frequency;
    
    for(int i = 0; i < nums.size(); ++i)
    {
        std::stringstream ss;
        ss << nums[i];
        std::string str = ss.str();
        if(isdigit(str[0]))
        {
            ++digit_frequency[str[0]];
        }
        else if(isdigit(str[1]))
        {
            ++digit_frequency[str[1]];
        }
    }
    
    std::map<char, int>::iterator it;
    for(it = digit_frequency.begin(); it != digit_frequency.end(); ++it)
    {
        std::cout << "Number " << it->first << " occurred " << it->second << " time(s).\n";
    }
    
    return 0;
}