C plus plus program for displaying position and frequency of a number in the given list?

Answer 1

#include<iostream>

#include<vector>

#include<list>

#include<map>

#include<time.h>

int main()

{

srand ((unsigned)time(nullptr));

// Create a list of 100 values in the range 0 to 9.

std::cout << "Number list:\t";

std::list<size_t> numbers;

for (size_t i=0; i<100; ++i)

{

numbers.push_back (rand()%10);

std::cout << numbers.back() << ' ';

}

std::cout << '\n' << std::endl;

// Determine position(s) of each number.

std::map<size_t, std::vector<size_t>> map;

size_t pos = 0;

for (auto it=numbers.begin(); it!=numbers.end(); ++it)

map[*it].push_back(pos++);

// Print number, frequency and position(s).

for (auto it=map.begin(); it!=map.end(); ++it)

{

std::cout << "Number:\t\t" << (*it).first << std::endl;

std::cout << "Frequency:\t" << (*it).second.size() << std::endl;

std::cout << "Postions:\t";

const std::vector<size_t>& positions = (*it).second;

for (auto it=positions.begin(); it!=positions.end(); ++it)

std::cout << (*it) << ' ';

std::cout << '\n' << std::endl;

}

}