705. 해시세트 설계

설명

예 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)

제약:

솔루션

솔루션 1

직관

암호

const int N = 113;
class MyHashSet {
private:
    vector<int> mySet[N];
    int find(int linkIndex, int target) {
        vector<int> &link = mySet[linkIndex];
        for (int i = 0; i < link.size(); i++) {
            if (link[i] == target) return i;
        }
        return -1;
    }

public:
    MyHashSet() {
    }

    void add(int key) {
        int linkIndex = key % N;
        int index = find(linkIndex, key);
        if (index == -1) mySet[linkIndex].push_back(key);
    }

    void remove(int key) {
        int linkIndex = key % N;
        int index = find(linkIndex, key);
        if (index != -1) mySet[linkIndex].erase(mySet[linkIndex].begin() + index);
    }

    bool contains(int key) {
        int linkIndex = key % N;
        int index = find(linkIndex, key);
        return index != -1;
    }
};

/**
 * 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);
 */

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