import java.util.HashSet;
import java.util.Hashtable;
import java.util.Iterator;
+import java.util.Map;
import java.util.Set;
public class Lattice<T> {
this.bottom = bottom;
table.put(top, new HashSet<T>());
+ table.put(bottom, new HashSet<T>());
}
return table.keySet();
}
+ public Map<T, Set<T>> getTable() {
+ return table;
+ }
+
+ public void setTable(Map<T, Set<T>> in) {
+ Set<T> keySet = in.keySet();
+ for (Iterator iterator = keySet.iterator(); iterator.hasNext();) {
+ T key = (T) iterator.next();
+ Set<T> setIn = in.get(key);
+ Set<T> newSet = new HashSet<T>();
+ newSet.addAll(setIn);
+ table.put(key, newSet);
+ }
+ }
+
+ public boolean put(T key) {
+ if (table.containsKey(key)) {
+ return false;
+ } else {
+ // new key, need to be connected with top/bottom
+ size++;
+ table.get(top).add(key);
+ Set<T> neightborSet = new HashSet<T>();
+ neightborSet.add(bottom);
+ table.put(key, neightborSet);
+ return true;
+ }
+ }
+
public boolean put(T key, T value) {
+
+ if (isComparable(key, value) && isGreaterThan(key, value)) {
+ // this relation already exists
+ return false;
+ }
+
Set<T> s;
Set<T> topNeighbor = table.get(top);
-
if (table.containsKey(key)) {
s = table.get(key);
} else {
size++;
s.add(value);
- if (!table.containsKey(value)) {
- Set<T> lowerNeighbor = new HashSet<T>();
- lowerNeighbor.add(bottom);
- table.put(value, lowerNeighbor);
+ if ((!table.containsKey(value)) && (!value.equals(bottom))) {
+ Set<T> lowerNeighbor = new HashSet<T>();
+ lowerNeighbor.add(bottom);
+ table.put(value, lowerNeighbor);
}
// if value is already connected with top, it is no longer to be
- topNeighbor.remove(value);
+ if (!key.equals(top)) {
+ topNeighbor.remove(value);
+ }
// if key is already connected with bottom,, it is no longer to be
- table.get(key).remove(getBottomItem());
+ if (!value.equals(getBottomItem())) {
+ table.get(key).remove(getBottomItem());
+ }
return true;
} else
do {
oldReachableSize = reachableSet.size();
Set<T> nextLevelNeighbors = new HashSet<T>();
- for (Iterator<T> iterator = neighborSet.iterator(); iterator.hasNext(); ) {
- T element = iterator.next();
- Set<T> neighbors = get(element);
- if (neighbors != null) {
- nextLevelNeighbors.addAll(neighbors);
- reachableSet.addAll(neighbors);
- }
-
- if (reachableSet.contains(key)) {
- // found cycle
- return true;
- }
+ for (Iterator<T> iterator = neighborSet.iterator(); iterator.hasNext();) {
+ T element = iterator.next();
+ Set<T> neighbors = get(element);
+ if (neighbors != null) {
+ nextLevelNeighbors.addAll(neighbors);
+ reachableSet.addAll(neighbors);
+ }
+
+ if (reachableSet.contains(key)) {
+ // found cycle
+ return true;
+ }
}
neighborSet = nextLevelNeighbors;
} while (oldReachableSize != reachableSet.size());
return table.containsKey(o);
}
+ public boolean isComparable(T a, T b) {
+
+ Set<T> neighborSet = get(a);
+
+ if (a.equals(b)) {
+ return true;
+ } else if (neighborSet == null) {
+ return false;
+ } else if (neighborSet.contains(b)) {
+ return true;
+ } else {
+ boolean reachable = false;
+ for (Iterator<T> iterator = neighborSet.iterator(); iterator.hasNext();) {
+ T neighbor = iterator.next();
+ reachable = reachable || isComparable(neighbor, b);
+ }
+ return reachable;
+ }
+
+ }
+
public boolean isGreaterThan(T a, T b) {
+ Set<T> visited = new HashSet<T>();
+ return isGreaterThan(a, b, visited);
+
+ }
+
+ public boolean isGreaterThan(T a, T b, Set<T> visited) {
+
+ if (a.equals(b)) {
+ return false;
+ }
+
if (a.equals(top)) {
if (b.equals(top)) {
- return false;
+ return false;
}
return true;
}
return true;
} else {
boolean reachable = false;
- for (Iterator<T> iterator = neighborSet.iterator(); iterator.hasNext(); ) {
- T neighbor = iterator.next();
- reachable = reachable || isGreaterThan(neighbor, b);
+ for (Iterator<T> iterator = neighborSet.iterator(); iterator.hasNext();) {
+ T neighbor = iterator.next();
+ if (!visited.contains(neighbor)) {
+ visited.add(neighbor);
+ reachable = reachable || isGreaterThan(neighbor, b, visited);
+ }
}
return reachable;
}
Set<T> lowerSet = new HashSet<T>();
// get lower set of input locations
- for (Iterator<T> iterator = inputSet.iterator(); iterator.hasNext(); ) {
+ for (Iterator<T> iterator = inputSet.iterator(); iterator.hasNext();) {
T element = iterator.next();
lowerSet.addAll(getLowerSet(element, new HashSet<T>()));
lowerSet.add(element);
// an element of lower bound should be lower than every input set
Set<T> toberemoved = new HashSet<T>();
- for (Iterator<T> inputIterator = inputSet.iterator(); inputIterator.hasNext(); ) {
+ for (Iterator<T> inputIterator = inputSet.iterator(); inputIterator.hasNext();) {
T inputElement = inputIterator.next();
- for (Iterator iterator = lowerSet.iterator(); iterator.hasNext(); ) {
- T lowerElement = (T) iterator.next();
- if (!inputElement.equals(lowerElement)) {
- if (!isGreaterThan(inputElement, lowerElement)) {
- toberemoved.add(lowerElement);
- }
- }
+ for (Iterator iterator = lowerSet.iterator(); iterator.hasNext();) {
+ T lowerElement = (T) iterator.next();
+ if (!inputElement.equals(lowerElement)) {
+ if (!isGreaterThan(inputElement, lowerElement)) {
+ toberemoved.add(lowerElement);
+ }
+ }
}
}
lowerSet.removeAll(toberemoved);
// calculate the greatest element of lower set
// find an element A, where every lower bound B of lowerSet, B<A
- for (Iterator<T> iterator = lowerSet.iterator(); iterator.hasNext(); ) {
+ for (Iterator<T> iterator = lowerSet.iterator(); iterator.hasNext();) {
T lowerElement = iterator.next();
boolean isGreaterThanAll = true;
- for (Iterator<T> iterator2 = lowerSet.iterator(); iterator2.hasNext(); ) {
- T e = iterator2.next();
- if (!lowerElement.equals(e)) {
- if (!isGreaterThan(lowerElement, e)) {
- isGreaterThanAll = false;
- break;
- }
- }
+ for (Iterator<T> iterator2 = lowerSet.iterator(); iterator2.hasNext();) {
+ T e = iterator2.next();
+ if (!lowerElement.equals(e)) {
+ if (!isGreaterThan(lowerElement, e)) {
+ isGreaterThanAll = false;
+ break;
+ }
+ }
}
if (isGreaterThanAll) {
- return lowerElement;
+ return lowerElement;
}
}
return null;
Set<T> neighborSet = get(element);
if (neighborSet != null) {
lowerSet.addAll(neighborSet);
- for (Iterator<T> iterator = neighborSet.iterator(); iterator.hasNext(); ) {
- T neighbor = iterator.next();
- lowerSet = getLowerSet(neighbor, lowerSet);
+ for (Iterator<T> iterator = neighborSet.iterator(); iterator.hasNext();) {
+ T neighbor = iterator.next();
+ lowerSet = getLowerSet(neighbor, lowerSet);
}
}
return lowerSet;
}
+ public Set<Pair<T, T>> getOrderingPairSet() {
+ // return the set of pairs in the lattice
+
+ Set<Pair<T, T>> set = new HashSet<Pair<T, T>>();
+
+ Set<T> visited = new HashSet<T>();
+ Set<T> needtovisit = new HashSet<T>();
+ needtovisit.add(top);
+
+ while (!needtovisit.isEmpty()) {
+ T key = needtovisit.iterator().next();
+ Set<T> lowerSet = table.get(key);
+ if (lowerSet != null) {
+ for (Iterator iterator = lowerSet.iterator(); iterator.hasNext();) {
+ T lowerItem = (T) iterator.next();
+ set.add(new Pair(key, lowerItem));
+ if (!visited.contains(key)) {
+ needtovisit.add(lowerItem);
+ }
+ }
+ }
+ visited.add(key);
+ needtovisit.remove(key);
+ }
+ return set;
+ }
+
}
projects / IRC.git / blobdiff