int LRUCacheMiss(vector<int> input, int maxSize) {
typedef list<int> LI;
typedef list<int>::iterator LII; // key iterator
typedef unordered_map<int, LII> MLII; // key, (key iterator)
LI cache;
MLII check;
int count = 0;
for (int i = 0; i < input.size(); i++) {
if (check.count(input[i]) > 0) {
// found in the LRU cache.
cache.erase(check[input[i]]);
cache.push_front(input[i]);
check[input[i]] = cache.begin();
}
else {
// not found, miss happens.
count++;
cache.push_front(input[i]);
check[input[i]] = cache.begin();
if (cache.size() > maxSize) {
int key = cache.back();
cache.pop_back();
check.erase(key);
}
}
}
return count;
}
void set(int key, int value) {
auto it = cache.find(key);
if(it!=cache.end()) {
update(it);
} else {
if(used.size()==cap) {
cache.erase(used.back());
used.pop_back();
}
used.push_front(key);
}
cache[key] = {value, used.begin()};
}