Online Election.java

// Runtime: 91 ms (Top 91.57%) | Memory: 51.6 MB (Top 89.43%)
class TopVotedCandidate {
    int[] persons;
    int[] times;
    int length;
    Map<Integer, Integer> voteCount;
    Map<Integer, Integer> voteLead;

    public TopVotedCandidate(int[] persons, int[] times) {
        this.persons = persons;
        this.times = times;
        length = times.length-1;
        int leadCount = 0;
        int leadPerson = -1;
        voteCount = new HashMap<>();
        voteLead = new HashMap<>();
        for(int i=0; i<=length; i++){
            int newCount = voteCount.getOrDefault(persons[i], 0) + 1;
            voteCount.put(persons[i], newCount);
            if(newCount >= leadCount){
                leadCount = newCount;
                leadPerson = persons[i];
            }
            voteLead.put(times[i], leadPerson);
        }
    }

    public int q(int t) {
        int leadPerson = -1;
        if(voteLead.containsKey(t)) {
            leadPerson = voteLead.get(t);
        }
        else if(t < times[0]){
            leadPerson = voteLead.get(times[0]);
        }
        else if(t > times[length]){
            leadPerson = voteLead.get(times[length]);
        }
        else {
            int low = 0;
            int high = length;
            while(low <= high){
                int mid = low + (high-low)/2;
                if(times[mid] > t) high = mid - 1;
                else low = mid + 1;
            }
            leadPerson = voteLead.get(times[high]);
        }
        return leadPerson;
    }
}