Dev - C++ - Codigo para Cuadrados medios

#include <iostream>

#include <sstream>

#include <cstdlib>

#include <ctime>

#include <string>

using namespace std;

int random();

int main()

{

    int x, sz, n;

    string str;

    cout << "\nIteraciones a realizar: ";

    cin >> n;

    srand( time(NULL) );

    x = random();

    for( int i = 1; i <= n; i++ ) {

        str = to_string( x );

        sz = str.length();

        sz = sz > 4 ? sz -= 4 : 0;

        if( sz % 2 == 0 ) {

            str.erase( 0, sz/2 );

            for( int j = 1; j <= sz/2; j++ ) str.pop_back();

        } else {

            str.erase( 0, sz/2 );

            for( int j = 1; j <= sz/2 + 1; j++ ) str.pop_back();

        }

        cout << "x = " << x << "\tcentral: " << str << endl;

        stringstream strInt( str );

        strInt >> x;

        x = x * x;

    }

}

int random()

{

    return rand() % 900 + 100;

}