// O(n^2) solution
public static int checkAns(ArrayList<String> A, ArrayList<String> Q) {
HashSet<String> dict = new HashSet<String>();
for (String s : Q) {
dict.add(s);
}
Pair<Integer, Integer> ans = new Pair<Integer, Integer>(0, A.size() - 1);
for (int l = 0; l < A.size(); ++l) {
HashMap<String, Integer> count = new HashMap<String, Integer>();
for (int r = l; r < A.size() && r - l < ans.getSecond() - ans.getFirst(); ++r) {
if (dict.contains(A.get(r))) {
count.put(A.get(r), count.containsKey(A.get(r)) ? count.get(A.get(r)) + 1 : 1);
}
if (count.size() == Q.size()) {
if (r - l < ans.getSecond() - ans.getFirst()) {
ans.setFirst(l);
ans.setSecond(r);
}
break;
}
}
count.clear();
}
return ans.getSecond() - ans.getFirst();
}
// @include
public static Pair<Integer, Integer> findSmallestSubarrayCoveringSubset(
ArrayList<String> A, ArrayList<String> Q) {
HashSet<String> dict = new HashSet<String>(Q);
HashMap<String, Integer> countQ = new HashMap<String, Integer>();
int l = 0, r = 0;
Pair<Integer, Integer> res = new Pair<Integer, Integer>(-1, -1);
while (r < A.size()) {
// Keep moving r until it reaches end or countQ has |Q| items.
while (r < A.size() && countQ.size() < Q.size()) {
if (dict.contains(A.get(r))) {
countQ.put(A.get(r), countQ.containsKey(A.get(r)) ? countQ.get(A.get(r)) + 1 : 1);
}
++r;
}
if (countQ.size() == Q.size()
&& // found |Q| keywords.
((res.getFirst() == -1 && res.getSecond() == -1)
|| r - 1 - l < res.getSecond() - res.getFirst())) {
res.setFirst(l);
res.setSecond(r - 1);
}
// Keep moving l until it reaches end or countQ has less |Q| items.
while (l < r && countQ.size() == Q.size()) {
if (dict.contains(A.get(l))) {
int it = countQ.get(A.get(l));
countQ.put(A.get(l), --it);
if (it == 0) {
countQ.remove(A.get(l));
if ((res.getFirst() == -1 && res.getSecond() == -1)
|| r - 1 - l < res.getSecond() - res.getFirst()) {
res.setFirst(l);
res.setSecond(r - 1);
}
}
}
++l;
}
}
return res;
}