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Copy pathLRUCache.cpp
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244 lines (224 loc) · 4.57 KB
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#include <cstdio>
#include <iostream>
#include <list>
#include <unordered_map>
using namespace std;
/****************** TLE Version *************************
struct CacheNode {
int key;
int value;
CacheNode(int k, int v):key(k), value(v){}
CacheNode(){}
};
class LRUCache {
int capacity;
list <CacheNode> cache;
public:
LRUCache(int capacity) {
this->capacity = capacity;
cache.clear();
}
int get(int key) {
if (capacity <= 0) {
return -1;
}
CacheNode tmp;
tmp.value = -1;
for (auto it = cache.begin(); it != cache.end(); ++it) {
if (it->key == key) {
tmp = (*it);
cache.erase(it);
break;
}
}
if (tmp.value == -1) {
return -1;
} else {
cache.push_front(tmp);
return tmp.value;
}
}
void set(int key, int value) {
CacheNode tmp;
tmp.value = -1;
for (auto it = cache.begin(); it!=cache.end(); ++it) {
if (it->key == key) {
tmp = (*it);
cache.erase(it);
break;
}
}
if (tmp.value == -1) {
if (cache.size() >= capacity) {
cache.pop_back();
}
cache.push_front(CacheNode(key, value));
} else {
tmp.value = value;
cache.push_front(tmp);
}
}
void print() {
for (auto it = cache.begin(); it != cache.end(); ++it) {
cout << it->key << "<->" << it->value << " ";
}
puts("");
}
};*/
/******************** Also TLE Version *****************
struct CacheNode {
int key;
int value;
CacheNode(int k, int v):key(k), value(v){}
CacheNode(){}
};
class LRUCache {
int capacity;
list <CacheNode> cache;
unordered_set <int> keySet;
public:
LRUCache(int capacity) {
this->capacity = capacity;
cache.clear();
keySet.clear();
}
int get(int key) {
if (keySet.find(key) == keySet.end()) {
return -1;
}
if (capacity <= 0) {
return -1;
}
CacheNode tmp;
for (auto it = cache.begin(); it != cache.end(); ++it) {
if (it->key == key) {
tmp = (*it);
cache.erase(it);
break;
}
}
cache.push_front(tmp);
return tmp.value;
}
void set(int key, int value) {
if (keySet.find(key) == keySet.end()) {
if (cache.size() >= capacity) {
keySet.erase(cache.back().key);
cache.pop_back();
}
cache.push_front(CacheNode(key, value));
keySet.insert(key);
}
CacheNode tmp;
for (auto it = cache.begin(); it!=cache.end(); ++it) {
if (it->key == key) {
tmp = (*it);
cache.erase(it);
break;
}
}
tmp.value = value;
cache.push_front(tmp);
}
void print() {
for (auto it = cache.begin(); it != cache.end(); ++it) {
cout << it->key << "<->" << it->value << " ";
}
puts("");
}
};*/
struct QNode {
int key;
int value;
QNode *pre;
QNode *next;
QNode(int k, int v):key(k),value(v),pre(NULL),next(NULL){}
QNode():key(0),value(-1),pre(NULL),next(NULL){}
};
class LRUCache {
int capacity;
QNode front, rear;
unordered_map <int, QNode*> keyAddress;
public:
LRUCache(int capacity) {
this->capacity = capacity;
front.next = &rear;
rear.pre = &front;
keyAddress.clear();
}
int get(int key) {
unordered_map<int,QNode*>:: iterator itr;
itr = keyAddress.find(key);
if (itr == keyAddress.end()) {
return -1;
}
QNode *cur = itr->second;
cur->pre->next = cur->next;
cur->next->pre = cur->pre;
cur->pre = &front;
cur->next = front.next;
front.next->pre = cur;
front.next = cur;
return cur->value;
}
void set(int key, int value) {
if (capacity == 0) {
return ;
}
unordered_map<int,QNode*>::iterator itr;
QNode *tmp;
itr = keyAddress.find(key);
if (itr == keyAddress.end()) {
tmp = new QNode(key, value);
keyAddress.insert(pair<int, QNode*>(key, tmp));
} else {
tmp = itr->second;
tmp->value = value;
tmp->pre->next = tmp->next;
tmp->next->pre = tmp->pre;
}
if (keyAddress.size() > capacity) {
keyAddress.erase(rear.pre->key);
rear.next = rear.pre;
rear.pre = rear.pre->pre;
rear.pre->next = &rear;
delete rear.next;
rear.next = NULL;
}
tmp->next = front.next;
tmp->next->pre = tmp;
front.next = tmp;
tmp->pre = &front;
}
void print() {
QNode * cur = front.next;
while (cur->next) {
cout << cur->key << "<->" << cur->value << " ";
cur = cur->next;
}
puts("");
}
};
int main() {
LRUCache cache(5);
while (1) {
cout << "choose operation (0 for get, 1 for set) >>";
int opt;
cin >> opt;
if (opt == 0) {
int key;
cout << "input the key >>" ;
cin >> key;
cout << "result >>" << cache.get(key) << endl;
} else if (opt == 1) {
int key, value;
cout << "intput key and value >>";
cin >> key >> value;
cache.set(key, value);
cout << "result: ";
cache.print();
puts("=======================");
}
}
return 0;
}