Mega Code Archive
Array Set
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/* Copyright (c) 2006, 2009, Carl Burch. License information is located in the
* com.cburch.logisim.Main source code and at www.cburch.com/logisim/. */
import java.util.AbstractSet;
import java.util.ConcurrentModificationException;
import java.util.Iterator;
import java.util.NoSuchElementException;
public class ArraySet extends AbstractSet {
private static final Object[] EMPTY_ARRAY = new Object[0];
private class ArrayIterator implements Iterator {
int itVersion = version;
int pos = 0; // position of next item to return
boolean hasNext = values.length > 0;
boolean removeOk = false;
public boolean hasNext() {
return hasNext;
}
public Object next() {
if(itVersion != version) {
throw new ConcurrentModificationException();
} else if(!hasNext) {
throw new NoSuchElementException();
} else {
Object ret = values[pos];
++pos;
hasNext = pos < values.length;
removeOk = true;
return ret;
}
}
public void remove() {
if(itVersion != version) {
throw new ConcurrentModificationException();
} else if(!removeOk) {
throw new IllegalStateException();
} else if(values.length == 1) {
values = EMPTY_ARRAY;
++version;
itVersion = version;
removeOk = false;
} else {
Object[] newValues = new Object[values.length - 1];
if(pos > 1) {
System.arraycopy(values, 0, newValues, 0, pos - 1);
}
if(pos < values.length) {
System.arraycopy(values, pos, newValues, pos - 1, values.length - pos);
}
values = newValues;
--pos;
++version;
itVersion = version;
removeOk = false;
}
}
}
private int version = 0;
private Object[] values = EMPTY_ARRAY;
public ArraySet() { }
public Object[] toArray() {
return values;
}
public Object clone() {
ArraySet ret = new ArraySet();
if(this.values == EMPTY_ARRAY) {
ret.values = EMPTY_ARRAY;
} else {
ret.values = (Object[]) this.values.clone();
}
return ret;
}
public void clear() {
values = EMPTY_ARRAY;
++version;
}
public boolean isEmpty() {
return values.length == 0;
}
public int size() {
return values.length;
}
public boolean add(Object value) {
int n = values.length;
for(int i = 0; i < n; i++) {
if(values[i].equals(value)) return false;
}
Object[] newValues = new Object[n + 1];
System.arraycopy(values, 0, newValues, 0, n);
newValues[n] = value;
values = newValues;
++version;
return true;
}
public boolean contains(Object value) {
for(int i = 0, n = values.length; i < n; i++) {
if(values[i].equals(value)) return true;
}
return false;
}
public Iterator iterator() {
return new ArrayIterator();
}
public static void main(String[] args) throws java.io.IOException {
ArraySet set = new ArraySet();
java.io.BufferedReader in = new java.io.BufferedReader(
new java.io.InputStreamReader(System.in));
while(true) {
System.out.print(set.size() + ":"); //OK
for(Iterator it = set.iterator(); it.hasNext(); ) {
System.out.print(" " + it.next()); //OK
}
System.out.println(); //OK
System.out.print("> "); //OK
String cmd = in.readLine();
if(cmd == null) break;
cmd = cmd.trim();
if(cmd.equals("")) {
;
} else if(cmd.startsWith("+")) {
set.add(cmd.substring(1));
} else if(cmd.startsWith("-")) {
set.remove(cmd.substring(1));
} else if(cmd.startsWith("?")) {
boolean ret = set.contains(cmd.substring(1));
System.out.println(" " + ret); //OK
} else {
System.out.println("unrecognized command"); //OK
}
}
}
}
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