title
Design a HashSet without using any built-in hash table libraries.
To be specific, your design should include these functions:
- add(value): Insert a value into the HashSet.
- contains(value) : Return whether the value exists in the HashSet or not.
- remove(value): Remove a value in the HashSet. If the value does not exist in the HashSet, do nothing.
Example:
MyHashSet hashSet = new MyHashSet();
hashSet.add(1);
hashSet.add(2);
hashSet.contains(1); // returns true
hashSet.contains(3); // returns false (not found)
hashSet.add(2);
hashSet.contains(2); // returns true
hashSet.remove(2);
hashSet.contains(2); // returns false (already removed)
Note:
- All values will be in the range of [0, 1000000].
- The number of operations will be in the range of [1, 10000].
- Please do not use the built-in HashSet library.
solution
class MyHashSet {
public:
/** Initialize your data structure here. */
int data[100001] = {0};
MyHashSet() {
}
void add(int key) {
if(data[key]==0)
data[key]++;
}
void remove(int key) {
if(data[key]>0)
data[key]--;
}
/** Returns true if this set contains the specified element */
bool contains(int key) {
return data[key]>0;
}
};
/**
* Your MyHashSet object will be instantiated and called as such:
* MyHashSet obj = new MyHashSet();
* obj.add(key);
* obj.remove(key);
* bool param_3 = obj.contains(key);
*/