/
FrequencyTracker.java
46 lines (34 loc) · 990 Bytes
/
FrequencyTracker.java
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// https://leetcode.com/problems/frequency-tracker
class FrequencyTracker {
int[] map = new int[100001];
int[] rev = new int[200001];
public FrequencyTracker() {
}
public void add(int number) {
int prevFreq = map[number];
map[number] += 1;
if (prevFreq != 0) {
rev[prevFreq] -= 1;
}
rev[map[number]] += 1;
}
public void deleteOne(int number) {
int prevFreq = map[number];
if (prevFreq != 0) {
map[number] -= 1;
rev[prevFreq] -= 1;
}
if (map[number] != 0)
rev[map[number]] += 1;
}
public boolean hasFrequency(int frequency) {
return rev[frequency] > 0;
}
}
/**
* Your FrequencyTracker object will be instantiated and called as such:
* FrequencyTracker obj = new FrequencyTracker();
* obj.add(number);
* obj.deleteOne(number);
* boolean param_3 = obj.hasFrequency(frequency);
*/