/**
* Back-end to pick using BFS.
*
* @param limit maximum value of combinations
* @param items object value table
* @return solution
*/
public static <T> Pack<T> breadthFirstSearch(Long limit, AbstractMap<T, Long> items) {
if (Pack.needSearch(limit, items)) {
return new Pack<T>(limit, new ArrayList<T>(items.keySet()));
}
ArrayList<Pack<T>> table = new ArrayList<Pack<T>>();
table.add(new Pack<T>());
for (Entry<T, Long> e : items.entrySet()) {
ArrayList<Pack<T>> tmp = new ArrayList<Pack<T>>();
for (Pack<T> p : table) {
Long newSize = p.getScore() + e.getValue();
if (newSize <= limit) {
ArrayList<T> newDirs = new ArrayList<T>(p.getItems());
newDirs.add(e.getKey());
tmp.add(new Pack<T>(newSize, newDirs));
}
}
table.addAll(table.size(), tmp);
}
Pack<T> max = new Pack<T>();
for (Pack<T> p : table) {
if (p.getScore() >= max.getScore()) {
max = p;
}
}
return max;
}
public Pack<T> call() {
while (!this.canStop()) {
this.crossOver();
this.mutation();
Collections.sort(this.population_);
this.population_.subList(this.table_.size(), this.population_.size()).clear();
}
Cell<T> survivor = this.population_.get(0);
Pack<T> result = new Pack<T>(survivor.getValue(), new ArrayList<T>());
for (Entry<T, Boolean> e : survivor.getTable().entrySet()) {
if (e.getValue()) {
result.getItems().add(e.getKey());
}
}
return result;
}