706. Design HashMap

题目

Design a HashMapwithout using any built-in hash table libraries.

To be specific, your design should include these functions:

put(key, value) :Insert a (key, value) pair into the HashMap. If the value already exists in the HashMap, update the value.
get(key): Returns the value to which the specified key is mapped, or -1 if this map contains no mapping for the key.
remove(key) :Remove the mapping for the value key if this map contains the mapping for the key.

Example:

MyHashMap hashMap = new MyHashMap();
hashMap.put(1, 1);
hashMap.put(2, 2);
hashMap.get(1);      // returns 1
hashMap.get(3);      // returns -1 (not found)
hashMap.put(2, 1);     // update the existing value
hashMap.get(2);      // returns 1
hashMap.remove(2);     // remove the mapping for 2
hashMap.get(2);      // returns -1 (not found)

Note:

All keys and 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 HashMap library.

解题思路

见程序注释