Solution
Time: O(nlogn)
Space: O(1)
public class Solution {
public int solve(ArrayList<Integer> A) {
Collections.sort(A);
for (int i = 1; i < A.size(); i ++) {
int curr = A.get(i);
int prev = A.get(i - 1);
if (prev != curr) {
int number_of_int_greater_than_prev = A.size() - i;
if (prev == number_of_int_greater_than_prev) {
return 1;
}
}
}
if (A.get(A.size() - 1) == 0) return 1;
return -1;
}
}