| using System;
using System.Collections;
public class StringSet {
private int capacity;
private static int DefaultCapacity = 10;
private string[] store;
private int next;
public StringSet(int capacity){
this.capacity = capacity;
store = new string[capacity];
next = 0;
}
public StringSet(): this(DefaultCapacity){
}
public StringSet(string[] elements): this(elements.Length){
foreach(string el in elements) this.Insert(el);
}
// Copy constructor
public StringSet(StringSet s): this(s.capacity){
foreach(string el in s) this.Insert(el);
}
public bool Member(string element){
for(int idx = 0; idx < next; idx++)
if (element.Equals(store[idx]))
return true;
return false;
}
public void Insert(string element){
if (!this.Member(element)){
if (this.Full){
Console.WriteLine("[Resize to {0}]", capacity * 2);
Array.Resize<string>(ref store, capacity * 2);
capacity = capacity * 2;
}
store[next] = element;
next++;
}
}
public void Delete(string element){
bool found = false;
int foundIdx = 0;
for(int idx = 0; !found && (idx < next); idx++){
if (element.Equals(store[idx])){
found = true;
foundIdx = idx;
}
}
if (found){ // shift remaining elements left
for(int idx = foundIdx+1; idx < next; idx++)
store[idx-1] = store[idx];
store[next-1] = default(string);
next--;
}
}
public int Count{
get{
return next;
}
}
// Is this set a subset of other
public bool Subset(StringSet other){
foreach(string e in this)
if (!other.Member(e))
return false;
return true;
}
private bool Full{
get{
return next == capacity;
}
}
public IEnumerator GetEnumerator (){
return new SetEnumerator(this);
}
private class SetEnumerator: IEnumerator{
private readonly StringSet set;
private int idx;
public SetEnumerator (StringSet s){
this.set = s;
idx = -1; // position enumerator outside range
}
public Object Current{
get {
return set.store[idx];
}
}
public bool MoveNext(){
if (idx < set.next - 1){
idx++;
return true;
}
else
return false;
}
public void Reset(){
idx = -1;
}
public void Dispose(){
}
}
public override string ToString(){
string elRes = "";
for(int idx = 0; idx < next; idx++)
elRes += " " + store[idx];
return "{" + elRes + " "+ "}";
}
} |