Thread: Vector -> int

> cout << "one = " one << endl;
> cout << "two = " two << endl;
Also you are missing some << operators on these two lines.

Swoopy:
That is not the actual program, but a quick sample showing the problem, I typed it fast here, and I forgot to place "<<"

anyway here is my actual program, now I am passing the vector by refrance.

Code:

#include <cstdlib> 
#include <iostream>
#include <vector>

using namespace std;

long int size = 10000;
void print(vector <long int> &arr, int size);
void h_ify(vector <long int> &arr,int i);
void make(vector <long int> &arr);
void sort_me(vector <long int> &arr);
int left(int i) ;
int right(int i) ;
///////////////////////////////

int main() 
{
vector <long int> a ; 

srand((unsigned)time(0));
for (int i = 0; i <= size; i++){     
    int x = rand(); 
    a.push_back(x);
}
   
   sort_me(a);

  system ("pause");
 return 0;
}

///////////////////////////////

void print(vector <long int> &a, int size) {
  for (int i = 0; i < size; i++) {
    cout << a[i] << " ";
  }
  cout << endl;
}

///////////////////////////////

int parent(int i) 
{
if(i==1)
return 0;

if(i&#37;2==0)
    return ( (i / 2)-1);
else
    return ( (i / 2));
}

int left(int i) {
  return (2 * i) + 1;
}

int right(int i) {
  return (2 * i) + 2;
}
///////////////////////////////


void h_ify(vector <long int> &a,int i) {
  int great;
  int l = left(i);
  int r = right(i);
  
  if ( (a[l] > a[i]) && (l < size)) 
    great = l;
  else 
    great = i;

  
  if ( (a[r] > a[great]) && (r < size)) 
    great = r;


  if (great != i) {
    int temp = a[i];
    a[i] = a[great];
    a[great] = temp;
    h_ify(a, great);
  }
  

}

///////////////////////////////

void make(vector <long int> &a) {
for (int i = (size - 1) / 2; i >= 0; i--) {
    h_ify(a, i);
   // print(a, size);
  }
}

///////////////////////////////

void sort_me(vector <long int> &a) {
    
  make(a);
 
  for (int i = size; i > 0; i--) {
    int temp = a[0];
    a[0] = a[size - 1];
    a[size - 1] = temp;
    size = size - 1;
    h_ify(a, 0);
  }
}

This works, only when size is smaller then about 3500 anything larger the program crashes, why and how can I fixt this problem ?

The depth of recursion of h_ify may have something to do with it.

Code:

 int one = (*xxx)[0];                           // <--- FIXED
 int two = (*xxx)[1];                           // <--- FIXED

Dont treat a pointer to a vector as if it were an array. You need to dereference that pointer to get to the vector first.

This line will cause a crash:

Code:

  if ( (a[l] > a[i]) && (l < size))

You need to reverse the order of the ANDed expressions. First test l < size and then index into the vector with l.

By the way, you don't need to pass the size argument with vector. The vector already knows its size which is available to you through the size() member.