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This is the class I created to make a MinHeap from data that is being inserted into it:

```
public class MinHeap
{
protected int [] a;
protected int lastindx;
public MinHeap()
{
lastindx = 0; // heap starts at a[1]
a = new int[1];
}
// is the heap empty?
public boolean isEmpty()
{
return lastindx < 1; // heap starts at a[1]
}
// how many items in the heap?
public int size()
{
return lastindx; // heap starts at a[1]
}
// remove and return the maximum item, reconnect and restructure
// throws ItemNotFound if there is no maximum item
public int deleteMin() throws ItemNotFound
{
if (isEmpty())
throw new ItemNotFound("Cannot extractmax() on empty max heap");
int temp = a[1];
a[1] = a[lastindx];
lastindx--;
percDown(a, 1, lastindx);
return temp;
}
// insert the new item x and percolate it up into place
public void insert(int x)
{
lastindx++;
if (lastindx==a.length)
expandArray();
decreaseKey(lastindx,x);
}
// dump out the heap in array index order (level order)
public void dumpHeap()
{
for(int i = 1; i < lastindx; i++)
System.out.print(a[i] + " ");
System.out.println();
}
//------------- private support methods ----------------------
// left child of a[i]
private int LC(int i)
{
return 2*i;
}
// right child of a[i]
private int RC(int i)
{
return 2*i+1;
}
// parent of a[i]
private int P(int i)
{
return i/2;
}
// swap a[i] and a[j]
private void swap(int i, int j)
{
int t = a[i];
a[i] = a[j];
a[j] = t;
}
// percolate upward from a[k], n is the size of the heap
// (i.e., a[n] is the last occupied slot)
private void percDown(int[] a, int k, int n)
{
int smallest = k;
int temp = 0;
if(LC(k) <= n && a[LC(k)] > a[k])
smallest = LC(k);
if(RC(k) <= n && a[RC(k)] > a[smallest])
smallest = RC(k);
if(smallest != k)
{
temp = a[k];
a[k] = a[smallest];
a[smallest] = temp;
percDown(a, smallest, n);
}
}
// increase the value of the key at a[i] and percolate it upward, if needed
private void decreaseKey(int i, int newval)
{
a[i] = newval;
while ((i>1) && (a[P(i)] < a[i]))
{
swap(i,P(i));
i = P(i);
}
}
// double the size of the array a[]
private void expandArray()
{
int[] t = new int [2*a.length];
for(int i = 0; i < a.length; i++)
{
t[i] = a[i];
}
a = t;
}
}
```

However, I'm having problems with this sorting the data I insert into it. I'm inserting character frequencies(found from a text file) to the heap, but the resulting hep isn't sorted properly for me to go ahead with the rest of the program.

This is what I use to insert data into the MinHeap:

```
for(int i = 0; i < f.length; i++)
{
if(f[i] > 0)
mih.insert(f[i]);
}
```

Using the dumpHeap(); method I get the following results(example insert):

11 2 7 2

Instead of:

11 7 2 2

Is there something wrong with my MinHeap class? Or is something else wrong with the program?

*Edited 6 Years Ago by JainishP*: n/a