We can implement tree by arrays. Likewise, this program shows how to implement set using arrays:
public class Set<T> {
private T arrayElement[];
int size =0;
public Set(){
this.arrayElement = null;
}
public Set(T[] element){
arrayElement = element;
size = arrayElement.length;
}
/**
*add element to set. A check is made to identify whether element is present or not.
*If not the element can be inserted.
* @param element
*/
public void addElement(T element){
if(!contains(element)){
if(size == arrayElement.length){
incrementArray();
}
arrayElement[size++] = element;
}
}
/**
* to check is element is present or not.
* @param elem
* @return boolean
*/
public boolean contains(T elem){
if (elem == null) {
for (int i = 0; i < size; i++)
if (arrayElement[i]==null)
return true;
} else {
for (int i = 0; i < size; i++)
if (elem.equals(arrayElement[i]))
return true;
}
return false;
}
/**
* return the size of set.
* @return int
*/
public int size(){
if(arrayElement != null){
return arrayElement.length;
}else
return 0;
}
public void clear(){
arrayElement = null;
}
public String toString(){
if(arrayElement == null || arrayElement.length ==0 ){
return“[EMPTY]“;
}else{
String toStr=”[";
for(int i=0;i<arrayElement.length;i++){
toStr+=arrayElement[i]+”,”;
}
toStr+=”]”;
return toStr;
}
}
/**
* to check whether set is empty or not
* @return
*/
public boolean isEmpty(){
if(arrayElement == null || arrayElement.length ==0 )
return true;
else
return false;
}
/**
* this function is used to increment the size of an array
*
*/
private void incrementArray(){
T[] temparray = arrayElement;
int tempsize=size+5;
arrayElement =(T[]) new Object[tempsize];
System.arraycopy(temparray, 0, arrayElement, 0, size);
}
}//Set class ends
