leetcode 146 LRU 缓存机制
作者:互联网
简介
使用了C++自带的实现deque 和 unordered_map
code
class LRUCache {
public:
unordered_map<int, bool> map;
unordered_map<int, int> mapV;
deque<int> q;
int capacity;
LRUCache(int capacity) {
this->capacity = capacity;
}
int get(int key) {
if(map[key]){
for(auto it=q.begin(); it != q.end(); it++){
if(*it == key){
q.erase(it);
break;
}
}
// if(q.size() == capacity) {
// map[q.front()] = false;
// q.pop_front();
// }
q.push_back(key);
map[key] = true;
return mapV[key];
}
return -1;
}
void put(int key, int value) {
if(map[key]) {
mapV[key] = value;
for(auto it=q.begin(); it != q.end(); it++){
if(*it == key){
q.erase(it);
break;
}
}
q.push_back(key);
}else{
if(q.size() == capacity){
map[q.front()] = false;
q.pop_front();
}
q.push_back(key);
map[key] = true;
mapV[key] = value;
}
}
};
/**
* Your LRUCache object will be instantiated and called as such:
* LRUCache* obj = new LRUCache(capacity);
* int param_1 = obj->get(key);
* obj->put(key,value);
*/
class LRUCache extends LinkedHashMap<Integer, Integer>{
private int capacity;
public LRUCache(int capacity) {
super(capacity, 0.75F, true);
this.capacity = capacity;
}
public int get(int key) {
return super.getOrDefault(key, -1);
}
public void put(int key, int value) {
super.put(key, value);
}
@Override
protected boolean removeEldestEntry(Map.Entry<Integer, Integer> eldest) {
return size() > capacity;
}
}
java 直接 使用了LinkedHashMap 然后 重载了removeEldestEntry函数, 对于输入的, 如果个数大于设定的容量将会删除.
java这个也太作弊了, 不过一般也很少有人会记住 LinkedHashMap这个名字.
还有removeEldestEntry这个名字.
标签:146,map,capacity,int,value,LRU,key,leetcode,LRUCache 来源: https://www.cnblogs.com/eat-too-much/p/14778166.html