哈希表//设计哈希映射
不使用任何内建的哈希表库设计一个哈希映射
具体地说，你的设计应该包含以下的功能
put(key, value)：向哈希映射中插入(键,值)的数值对。如果键对应的值已经存在，更新这个值。get(key)：返回给定的键所对应的值，如果映射中不包含这个键，返回-1。remove(key)：如果映射中存在这个键，删除这个数值对。
示例：
MyHashMap hashMap = new MyHashMap(); hashMap.put(1, 1); hashMap.put(2, 2); hashMap.get(1); // 返回 1 hashMap.get(3); // 返回 -1 (未找到) hashMap.put(2, 1); // 更新已有的值 hashMap.get(2); // 返回 1 hashMap.remove(2); // 删除键为2的数据 hashMap.get(2); // 返回 -1 (未找到)
注意：
- 所有的值都在
[1, 1000000]的范围内。 - 操作的总数目在
[1, 10000]范围内。 - 不要使用内建的哈希库。
class MyHashMap {
private int[] buckets;
/** Initialize your data structure here. */
public MyHashMap() {
buckets = new int[1000000];
for(int i = 0; i < buckets.length; i++)
buckets[i] = -1;
}
/** value will always be non-negative. */
public void put(int key, int value) {
buckets[key] = value;
}
/** Returns the value to which the specified key is mapped, or -1 if this map contains no mapping for the key */
public int get(int key) {
return buckets[key];
}
/** Removes the mapping of the specified value key if this map contains a mapping for the key */
public void remove(int key) {
buckets[key] = -1;
}
}
/**
* Your MyHashMap object will be instantiated and called as such:
* MyHashMap obj = new MyHashMap();
* obj.put(key,value);
* int param_2 = obj.get(key);
* obj.remove(key);
*/class MyHashMap {
public:
/** Initialize your data structure here. */
MyHashMap() {
buckets = vector<int>(1000001,-1);
}
/** value will always be non-negative. */
void put(int key, int value) {
buckets[key] = value;
}
/** Returns the value to which the specified key is mapped, or -1 if this map contains no mapping for the key */
int get(int key) {
return buckets[key];
}
/** Removes the mapping of the specified value key if this map contains a mapping for the key */
void remove(int key) {
buckets[key] = -1;
}
private:
vector<int> buckets;
};
/**
* Your MyHashMap object will be instantiated and called as such:
* MyHashMap obj = new MyHashMap();
* obj.put(key,value);
* int param_2 = obj.get(key);
* obj.remove(key);
*/
