Step by Step solution about How to resolve the algorithm Sort numbers lexicographically step by step in the C++ programming language

The provided code snippet includes a C++ program that sorts a vector of integers lexicographically, meaning it arranges the elements in a way that is consistent with the natural ordering of strings when the elements are represented as strings of digits.

Firstly, it defines a function called lexicographical_sort that takes a vector of integers as an argument. Within this function,

• It initializes an empty vector of strings (strings) with the same size as the input vector (numbers).

• It converts each integer in numbers into a string representation and stores it in the strings vector using std::transform.

• The strings vector is sorted lexicographically using std::sort.

• Finally, it converts the sorted strings back to integers and stores them in the original numbers vector.

The lexicographically_sorted_vector function returns a new vector of integers that is sorted lexicographically. It accepts an integer n as input and creates a vector of size n (or 2 if n is less than 1). It initializes the vector with values from 1 to n using std::iota and then sorts it lexicographically using lexicographical_sort.

In the main function, it iterates through several values of i and prints the lexicographically sorted vector returned by lexicographically_sorted_vector(i) for each value. It demonstrates the sorting for different inputs, including positive, negative, and zero.

The print_vector function is a utility function used to print the contents of a vector to the standard output stream. It takes a vector and an output stream as arguments and prints the vector elements enclosed in square brackets, separated by commas.

In summary, this code snippet defines functions to sort a vector of integers lexicographically and provides examples of how it works for different input values.

#include <algorithm>
#include <iostream>
#include <numeric>
#include <string>
#include <vector>

void lexicographical_sort(std::vector<int>& numbers) {
    std::vector<std::string> strings(numbers.size());
    std::transform(numbers.begin(), numbers.end(), strings.begin(),
                   [](int i) { return std::to_string(i); });
    std::sort(strings.begin(), strings.end());
    std::transform(strings.begin(), strings.end(), numbers.begin(),
                   [](const std::string& s) { return std::stoi(s); });
}

std::vector<int> lexicographically_sorted_vector(int n) {
    std::vector<int> numbers(n >= 1 ? n : 2 - n);
    std::iota(numbers.begin(), numbers.end(), std::min(1, n));
    lexicographical_sort(numbers);
    return numbers;
}

template <typename T>
void print_vector(std::ostream& out, const std::vector<T>& v) {
    out << '[';
    if (!v.empty()) {
        auto i = v.begin();
        out << *i++;
        for (; i != v.end(); ++i)
            out << ',' << *i;
    }
    out << "]\n";
}

int main(int argc, char** argv) {
    for (int i : { 0, 5, 13, 21, -22 }) {
        std::cout << i << ": ";
        print_vector(std::cout, lexicographically_sorted_vector(i));
    }
    return 0;
}