Why do I need pointer

Hi. I have a vector of pointers. When I try to return v[i] from the following function and then try to output the values to the console, the program crashes.

Code:

Huff* findMinimum(vector<Huff*>& v)
{
     int i, minCo=v[0]->count;
     char minCh=v[0]->ch;
     for(i=1; i<v.size(); i++)
     {
         if(v[i]->count < minCo)
         {
             minCo=v[i]->count;
             minCh=v[i]->ch;
         }
     }
     return v[i];
}

However, once I do this:

Code:

Huff* findMinimum(vector<Huff*>& v)
{
     int i, minCo=v[0]->count;
     char minCh=v[0]->ch;
     Huff* h3;
     for(i=1; i<v.size(); i++)
     {
         if(v[i]->count < minCo)
         {
             minCo=v[i]->count;
             minCh=v[i]->ch;
             h3=v[i];
         }
     }
     return h3;
}

The program will output the values fine? Isn't v[i] a pointer? I'm baffled. Thanks, Steve

Code:

#include<iostream>
#include<string>
#include<vector>
#include<fstream>
#include<stack>
using namespace std;

struct Huff;

Huff* findMinimum(vector<Huff*>& v);

struct Huff
{
    Huff();
    int count;
    char ch;
    Huff* left;
    Huff* right;
    Huff* parent;
};

int main(int argc, char* argv[])
{
	if(argc<2)
	{
	    cout<<"Not enough arguments were provided."<<endl;
		return -1;
	}
    ifstream myFile(argv[1], ios::in);
	if(!myFile.is_open())
	{
	    cout<<"Unknown file specified."<<endl;
		return -1;
	}
	char cz;
    int i;
    vector<Huff*> values;
    while(myFile.get(cz))
    {
        if(cz < 'a' || cz > 'z')
            continue;
        for(i=0; i<values.size(); i++)
        {
            if(values[i]->ch == cz)
            {
                values[i]->count++;
                break;
            }
        }
        if(values.size()==i)
        {
            Huff* h = new Huff;
            h->ch=cz;
            h->count=1;
            values.push_back(h);
        }
     }
     for(i=0; i<values.size(); i++)
         cout<<values[i]->ch<<values[i]->count<<endl;
     Huff* h2;
     h2=findMinimum(values);
     cout<<h2->ch<<endl;
     cout<<h2->count<<endl;
     return 0;
}

Huff::Huff() : ch(0), count(0) { }

Huff* findMinimum(vector<Huff*>& v)
{
     int i, minCo=v[0]->count;
     char minCh=v[0]->ch;
     Huff* h3;
     for(i=1; i<v.size(); i++)
     {
         if(v[i]->count < minCo)
         {
             minCo=v[i]->count;
             minCh=v[i]->ch;
             h3=v[i];
         }
     }
     return h3;
}

>Isn't v[i] a pointer?
It's treated as one, yes. But because the loop terminated normally (when i == v.size()), v[i] is an out of bounds index. You can only access indices 0 to v.size() - 1.

Notice that you do not break out of the loop when the 'if' condition evaluates to true (or for that matter, the last time it does, which is the logical equivalent of your second piece of code). So, i keeps getting incremented until it no longer satisifies the loop condition (when i == v.size()), so you end up returning v[v.size()] which is, of course, out of bounds.

*edit*
Foiled! Grrr...

Glad you could see that! Wish I could have. Thanks again. Steve