0

Hi,

This is a very basic question, but I can't seem to get working, I've a set of numbers that I need to display in the following, this is a class function btw.

The ouput should be something like
{ 1, 2, 3, 4, 5} (there are {} brackets and each element is seperated by a comma).

void set::display()const
{
          
        cout << "{";
        for (int i = 0; i < setlist.size(); i++)
            if (setlist.at(i) == true) 
               cout<< i <<",";           
        cout << "}";
            
}

Just to explain, there are 100 indexes, if a particular index is true, say for example, 6 is true, the output would display 6.

There is also another code which gives me the largest number of the set.

int set::getLargest() const
{
     for (int i = setlist.size()-1; i >= 0; i--)
     {
         if (setlist.at(i) == true)
         return i;
     } 
}

btw setlist is actually a private which is vector<bool>setlist.

My initial idea was to use the getLargest function (which is also a class function) into the if statement, so it would be
if ((setlist.at(i)==true) && setlist.at(i) != setlist.getLargest(setlist.at(i))
cout << i << ",";

However, the compiler would not let me do that.

Can someone point me into the right direction of getting my display function to work?

Thanks.

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Last Post by Zohar
0

you don't really need the at() method, just index it just like an ordinary array if ((setlist[i]==true) && i != setlist.getLargest() Notice that method getLargest() does not take any parameters. Also note that getLargest() will return the index value not a value from the array.

Edited by Ancient Dragon: n/a

0

I'm getting const class std::vector<bool, std::allocator<bool>' has no member named getLargest'

That's the main problem here I guess, using a class function within another one.

I'll post the header file here...

#ifndef SETH
#define SETH
// definition of a set of integers 
#include <iostream>
#include <vector>
using namespace std;
const int DEFAULTSIZE = 100;

class set
{
  public :
   set(); // default constructor - constructs an empty  set of integers in range 0 to DEFAULTSIZE -1
   set(int n);
     // pre : n >= 0 and n <= 500000
     // post : constructs an empty  set of integers in range 0 to n-1
   bool empty() const;
     // pre : none
     // post : returns true if set empty and otherwise false
   bool isIn(int x) const; 
     // pre : none
     // post : returns true if x is in set and otherwise false
   void dump() const;
     // pre : none
     // post : dumps out the valus in set (separated by white space) 
   int getCardinality() const;
     // pre : none
     // post :  returns the number of elements in the set
   void insert(int x);
     // pre : none
     // post : inserts x into this set (if in range)
   int getSmallest() const;
     // pre : set is not empty
     // post : returns smallest element in the set
   int getLargest() const;  
     // pre : set is not empty
     // post : returns largest element in the set
   set unions(int x) const;
     // pre : none
     // post : returns the union of this set and x (if x in range)
   set unions(const set &other) const;
     // pre : both  sets are in same range (domain)
     // post : returns the union of this set and other set
   set intersect(int x) const;
     // pre :  none
     // post : returns the intersection of this set and x (if x in range)
   set intersect(const set &other) const;
     // pre : both sets are in same range (domain)
     // post : returns the intersection of this set and other set
   void display()const;
     // pre : none
     // displays the elements of this set enclosed in braces and
     // separated by commas eg {1,2,3} or {} (do not use backspace, delete etc)
   set difference(const set &other) const;
     // pre :  both sets are in same range (domain)
     // post : returns the difference of this set and other set
   set difference(int x)const;
     // pre : none
     // post : returns the difference of this set and x (if x in range)
   int getUpperRange()const;
     // pre : none
     // post : returns the upper value in the domain (upper range)
   bool isEqual (const set & other) const;
     // pre : both sets are in the same range (domain)
     // post : returns true if this set is equal to other set
  private:
     vector <bool> setlist;  // indicates set elements as true
     int cardinality; // number of items in set
     
}; 
#endif

Thanks for your help though.

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