How do you find the frequency of positive integers using C plus plus?

Answer 1

#include<iostream>

#include<iomanip>

#include<map>

#include<random>

#include<time.h>

std::default_random_engine generator;

std::uniform_int_distribution<unsigned> distribution (1, 10);

typedef std::map<unsigned, unsigned> freq_map;

int main()

{

std::cout << "Program to generate 1,000,000 random numbers in the range 1 to 10\n";

std::cout << "and to print the frequency table for all numbers generated.\n\n";

generator.seed ((unsigned) time (NULL));

freq_map fmap;

freq_map::iterator iter;

for (unsigned count=0; count<1000000; ++count)

{

unsigned number = distribution (generator);

iter = fmap.find (number);

if (iter == fmap.end())

{

fmap.insert (freq_map::value_type (number, 1));

}

else

{

++(iter->second);

}

}

for (iter = fmap.begin(); iter != fmap.end(); ++iter)

{

std::cout << "The number" << std::setw(3) << iter->first;

std::cout << " occurred" << std::setw(7) << iter->second << " times\n";

}

std::cout << std::endl;

}