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passed by reference but not getting it(vectors and sorting)

Macki (14)
I was assisted by Peter87, about passing by reference regarding vectors and sorting.. I attempted another try at introducing mode of array by way of vectors,
I know it works for preconfigured arrays, but I am really interested in vector arrays so I spliced it with a mode block from an array initialized by a specific
size .
I would like another brutal input or pointers on how vectors,arrays and modes work I have an idea I ran it through 20 times 2 hours sleep. The prog returns mode -1
though I have the values. I know it has something to do with vectors and passing
by reference , how do I break it down so I see the problem by hand tracing or by
line reading the prog without running it.. since I tried it on paper..
I am trying to understand algorithm of sorting.. how do you see the algo
for vecs..

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#include<iostream>
#include<vector>

using namespace std;
void showData(vector<int>);
void selectionSort(vector<int>&, int);
void sortedShowData(vector<int>&, int);
void findFreq( vector<int>&,int);
int main ()
{
vector<int> values;
int Size;
int mode=0;

cout<<"input the size of the array:";
cin>>Size;
for (int counter=0;counter<Size;counter++)
  {
  int no;
  cout<<"Value ["<<(counter+1)<<"]:";
  cin>>no;
  values.push_back(no);
 
  }
  cout<<"User Input..\n";
  showData(values); 
  selectionSort(values,Size);
  cout<<endl;
  cout<<"sorted"<<endl;
  sortedShowData(values,Size);
  cout<<endl;
  findFreq(values,Size);
  system("pause");

return 0;
}

void showData(vector<int> vect)
{
     for(int count=0; count<vect.size();count++)
     cout<<vect[count]<<endl;
}
void selectionSort(vector<int>& a,int)
{
     int startScan, minIndex, minValue;
    int s=a.size();
     for (int startScan=0; startScan<s-1;startScan++)
    {
     minIndex =startScan;
     minValue = a[startScan];
     for (int index =startScan+1; index<s;index++)
     {
         if (a[index]<minValue)
            {
             minValue =a[index];
             minIndex=index;
             }
      }
             a[minIndex]=a[startScan];
             a[startScan]=minValue;
    }        

}

void sortedShowData(vector<int>& b, int size)
{    size=b.size();
     for (int c=0;c<size; c++)
     cout<<b[c]<<endl;
     
}
void findFreq( vector<int>& cc, int)
{
     int mode=-1; 
     int pos=0; 
     int hi;
     int size=cc.size();
     int fqncy[size];
    int fval;
    int icount;
     for( icount=0; icount<size; icount++)
     
     fqncy[icount]=0;
            
            for(int kcount=0;kcount<size; kcount++)
                {
                    
                    if(cc[icount]==cc[kcount]&& &cc[icount]!=&cc[kcount])
                     fqncy[kcount]+=fqncy[kcount+1];
                      fval=fqncy[kcount];  
                } 
                hi=fqncy[0];
                for (int ind=1; ind<size;ind++)
                {
                    if (fqncy[ind]>hi)
                    {
                    hi= fqncy[ind];
                    pos=+ind;
                    }
               }
                for (int ind=0; ind<size; ind++)
                if (fqncy[ind]!=fqncy[ind+1]&&(ind+1)<size)
                {
                 mode= cc[pos];
                 }
                 cout<<"Mode:"<<mode<<endl;
                 cout<<"Freq Val:"<<fval<<endl;
                 

}


Sorry .. I found out I was missing a loop and wrong values for the array indexes.. am figuring out the freq val being invalid right now if it works I'll post it again

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#include<iostream>
#include<vector>

using namespace std;
void showData(vector<int>);
void selectionSort(vector<int>&, int);
void sortedShowData(vector<int>&, int);
void findFreq( vector<int>&,int);
int main ()
{
vector<int> values;
int Size;
int mode=0;

cout<<"input the size of the array:";
cin>>Size;
for (int counter=0;counter<Size;counter++)
  {
  int no;
  cout<<"Value ["<<(counter+1)<<"]:";
  cin>>no;
  values.push_back(no);
 
  }
  cout<<"User Input..\n";
  showData(values); 
  selectionSort(values,Size);
  cout<<endl;
  cout<<"sorted"<<endl;
  sortedShowData(values,Size);
  cout<<endl;
  findFreq(values,Size);
  system("pause");

return 0;
}

void showData(vector<int> vect)
{
     for(int count=0; count<vect.size();count++)
     cout<<vect[count]<<endl;
}
void selectionSort(vector<int>& a,int)
{
     int startScan, minIndex, minValue;
    int s=a.size();
     for (int startScan=0; startScan<s-1;startScan++)
    {
     minIndex =startScan;
     minValue = a[startScan];
     for (int index =startScan+1; index<s;index++)
     {
         if (a[index]<minValue)
            {
             minValue =a[index];
             minIndex=index;
             }
      }
             a[minIndex]=a[startScan];
             a[startScan]=minValue;
    }        

}

void sortedShowData(vector<int>& b, int size)
{    size=b.size();
     for (int c=0;c<size; c++)
     cout<<b[c]<<endl;
     
}
void findFreq( vector<int>& cc, int)
{
     int mode=-1; 
     int pos=0; 
     int hi;
     int size=cc.size();
     int fqncy[size];
    int fval;
    int count;
     for( count=0; count<size; count++)
     
     fqncy[count]=0;
            
            for(int kcount=0;kcount<size; kcount++)
                {
                  for(int icount=1;icount<size;  icount++)
                  {
                    if(cc[kcount]==cc[icount]&& &cc[icount]!=&cc[kcount])
                     fqncy[kcount]+=1;
                      fval=fqncy[kcount];  
                   } 
                 } 
                hi=fqncy[0];
                for (int ind=1; ind<size;ind++)
                {
                    if (fqncy[ind]>hi)
                    {
                    hi= fqncy[ind];
                    pos=+ind;
                    }
               }
                for (int ind=0; ind<size; ind++)
                if (fqncy[ind]!=fqncy[ind+1]&&(ind+1)<size)
                {
                 mode= cc[pos];
                 }
                 cout<<"Mode:"<<mode<<endl;
                 cout<<"Freq Val:"<<fval<<endl;
                 

}

Last edited on
Computergeek01 (5613)
STL containers are not data types, think of a vector as an array and pass a reference to it instead of the entire thing.
Macki (14)
Ok .. will let you know if it works.. later at night have to go to calc II class..
I appreciate the response.. if any what textbook material would you recommend to really understand algorithms and writing code.. i.e. thinking like
a machine.. I know its overkill.. I 'm just a little obsesssed with talking to computers. thanks again Computergeek01..

Max
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