Design a HashSet without using any built-in hash table libraries.
Implement MyHashSet class:
-
void add(key)Inserts the valuekeyinto the HashSet. -
bool contains(key)Returns whether the valuekeyexists in the HashSet or not. -
void remove(key)Removes the valuekeyin the HashSet. Ifkeydoes not exist in the HashSet, do nothing.
Example 1:
Input
["MyHashSet", "add", "add", "contains", "contains", "add", "contains", "remove", "contains"]
[[], [1], [2], [1], [3], [2], [2], [2], [2]]
Output
[null, null, null, true, false, null, true, null, false]
Explanation
MyHashSet myHashSet = new MyHashSet();
myHashSet.add(1); // set = [1]
myHashSet.add(2); // set = [1, 2]
myHashSet.contains(1); // return True
myHashSet.contains(3); // return False, (not found)
myHashSet.add(2); // set = [1, 2]
myHashSet.contains(2); // return True
myHashSet.remove(2); // set = [1]
myHashSet.contains(2); // return False, (already removed)
Constraints:
-
0 <= key <= 106 - At most
104calls will be made toadd,remove, andcontains.
SOLUTION:
import bisect
class MyHashSet:
def __init__(self):
self.size = 107
self.arr = [[] for i in range(self.size)]
def hfn(self, key):
key = ((key >> 16) ^ key) * 0x45d9f3b
key = ((key >> 16) ^ key) * 0x45d9f3b
key = (key >> 16) ^ key
return key % self.size
def add(self, key: int) -> None:
pos = bisect.bisect_left(self.arr[self.hfn(key)], key)
if pos >= len(self.arr[self.hfn(key)]) or self.arr[self.hfn(key)][pos] != key:
self.arr[self.hfn(key)].insert(pos, key)
def remove(self, key: int) -> None:
pos = bisect.bisect_left(self.arr[self.hfn(key)], key)
if pos < len(self.arr[self.hfn(key)]) and self.arr[self.hfn(key)][pos] == key:
del self.arr[self.hfn(key)][pos]
def contains(self, key: int) -> bool:
pos = bisect.bisect_left(self.arr[self.hfn(key)], key)
if pos < len(self.arr[self.hfn(key)]) and self.arr[self.hfn(key)][pos] == key:
return True
return False
# Your MyHashSet object will be instantiated and called as such:
# obj = MyHashSet()
# obj.add(key)
# obj.remove(key)
# param_3 = obj.contains(key)
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