Calcolatrice in C++(array di funzioni)

/*
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 */

/* 
 * File:   main.cpp
 * Author: alessandrobarazzuol
 *
 * Created on 1 febbraio 2020, 19.46
 */

#include <cstdlib>
#include<iostream>
#include <stdlib.h>

using namespace std;

int meno(int a,int b)
{
    return a-b;
}

int piu(int a, int b)
{
    
    return a+b;
}

int diviso(int a,int b)
{
    if(b!=0)
    return a/b;
    else
    exit(1);
}

int per(int a, int b)
{
    return a*b;
}


char op(int a)
{
    switch(a)
    {
        case 1:
            return '+';
           
            
        case 2:
            
            return '-';
            
        case 3:
            
            return '*';
            
        case 4:
            
            return '\\';
    }
}


using namespace std;

/*
 * 
 */
int main(int argc, char** argv) {

    
    int  (*calcolatrice[4])(int,int) ={piu,meno,per,diviso};
    int scelta,a,b;
    
    
    do
    {
        
        
        cout<<"\n1. +\n2. -\n3. *\n4. \\\n";
        cin>>scelta;
        cout<<"a= ";
        cin>>a;
        cout<<"b= ";
        cin>>b;
        cout<<a<<op(scelta)<<b<<" = ";
        switch(scelta)
        {
            
            case 1:
                cout<<calcolatrice[0](a,b);
               break;
               
            case 2:
                cout<<calcolatrice[1](a,b);
                break;
                
            case 3:
                cout<<calcolatrice[2](a,b);
                break;
                
            case 4:
                cout<<calcolatrice[3](a,b);
              
                break;
        }
        
       system("clear");
        
    }  while(1);
  
    
    
   
  
    
    
    return 0;
}