[LeetCode] 705. Design HashSet (C++)
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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.
最原始解法
class MyHashSet {
public:
/** Initialize your data structure here. */
MyHashSet() {
/*
All values will be in the range of [0, 1000000]
*/
data.resize(1000000,0);
/*
void resize( size_type size, TYPE val );
*/
}
void add(int key) {
data[key]=1;
}
void remove(int key) {
data[key]=0;
}
/** Returns true if this set contains the specified element */
bool contains(int key) {
return data[key]==1;
}
private:
/*
All values will be in the range of [0, 1000000]
*/
vector<int> data;
};
/**
* 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);
*/
/*
Submission Detail:
Runtime: 184 ms, faster than 20.61% of C++ online submissions for Design HashSet.
Memory Usage: 158.8 MB, less than 13.09% of C++ online submissions for Design HashSet.
*/
稍微优化
class MyHashSet {
public:
/** Initialize your data structure here. */
MyHashSet() {
/*
All values will be in the range of [0, 1000000]
*/
data.resize(1000,vector<int>());
/*
void resize( size_type size, TYPE val );
*/
}
void add(int key) {
int hashKey=key%1000;
data[hashKey].resize(1000,0);
data[hashKey][key/1000]=1;
}
void remove(int key) {
int hashKey=key%1000;
if(!data[hashKey].empty()) {
data[hashKey][key/1000]=0;
}
}
/** Returns true if this set contains the specified element */
bool contains(int key) {
int hashKey=key%1000;
return(!data[hashKey].empty() && data[hashKey][key/1000]==1);
}
private:
vector<vector<int>> data;
};
/**
* 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);
*/
/*
Submission Detail:
Runtime: 184 ms, faster than 20.61% of C++ online submissions for Design HashSet.
Memory Usage: 158.8 MB, less than 13.09% of C++ online submissions for Design HashSet.
*/
/*
Submission Detail:
Runtime: 136 ms, faster than 41.80% of C++ online submissions for Design HashSet.
Memory Usage: 92.3 MB, less than 21.43% of C++ online submissions for Design HashSet.
*/