problem0432

README

432. All O`one Data Structure

题目

Implement a data structure supporting the following operations:

1. Inc(Key) - Inserts a new key with value 1. Or increments an existing key by 1. Key is guaranteed to be a non-empty string.
2. Dec(Key) - If Key's value is 1, remove it from the data structure. Otherwise decrements an existing key by 1. If the key does not exist, this function does nothing. Key is guaranteed to be a non-empty string.
3. GetMaxKey() - Returns one of the keys with maximal value. If no element exists, return an empty string "".
4. GetMinKey() - Returns one of the keys with minimal value. If no element exists, return an empty string "".

Challenge: Perform all these in O(1) time complexity.

解题思路

见程序注释

Documentation

Index

• type AllOne
  • func Constructor() AllOne
  • func (a *AllOne) Dec(key string)
  • func (a *AllOne) GetMaxKey() string
  • func (a *AllOne) GetMinKey() string
  • func (a *AllOne) Inc(key string)

Types

type AllOne

type AllOne struct {
	// contains filtered or unexported fields
}

AllOne 是解题所需的结构

func Constructor

func Constructor() AllOne

Constructor initialize your data structure here.

func (*AllOne) Dec

func (a *AllOne) Dec(key string)

Dec decrements an existing key by 1. If Key's value is 1, remove it from the data structure.

func (*AllOne) GetMaxKey

func (a *AllOne) GetMaxKey() string

GetMaxKey returns one of the keys with maximal value.

func (*AllOne) GetMinKey

func (a *AllOne) GetMinKey() string

GetMinKey returns one of the keys with Minimal value.

func (*AllOne) Inc

func (a *AllOne) Inc(key string)

Inc inserts a new key <Key> with value 1. Or increments an existing key by 1.