public LinkedMapItem(string key, string value, LinkedMapItem prev, LinkedMapItem next = null)
{
this.key = key;
this.value = value;
this.prev = prev;
this.next = next;
}
public static void Solve()
{
using (var input = new StreamReader("linkedmap.in"))
{
using (var output = new StreamWriter("linkedmap.out"))
{
MyLinkedMap map = new MyLinkedMap();
LinkedMapItem lastItem = null;
LinkedMapItem deleted = null;
while (true)
{
string[] line = input.ReadLine()?.Trim().Split();
if (line == null)
{
break;
}
switch (line[0])
{
case "put":
lastItem = map.Put(new LinkedMapItem(line[1], line[2], lastItem));
break;
case "delete":
deleted = map.Delete(line[1]);
if (deleted?.key == lastItem?.key)
{
lastItem = deleted?.prev;
}
break;
case "get":
output.WriteLine(map.Get(line[1])?.value ?? "none");
break;
case "prev":
output.WriteLine(map.Prev(line[1])?.value ?? "none");
break;
case "next":
output.WriteLine(map.Next(line[1])?.value ?? "none");
break;
}
}
}
}
}
public LinkedMapItem Delete(string key)
{
int hashCode = Hash(key);
if (hashTable[hashCode] == null || !hashTable[hashCode].Exists(i => i.key == key))
{
return(null);
}
LinkedMapItem item = hashTable[hashCode].Find(i => i.key == key);
if (item.prev != null)
{
item.prev.next = item.next;
}
if (item.next != null)
{
item.next.prev = item.prev;
}
item = hashTable[hashCode].Find(i => i.key == key);
hashTable[hashCode].RemoveAll(i => i.key == key);
return(item);
}
public LinkedMapItem Put(LinkedMapItem item)
{
int hashCode = Hash(item.key);
if (hashTable[hashCode] == null)
{
hashTable[hashCode] = new List <LinkedMapItem>();
}
if (!hashTable[hashCode].Exists(i => i.key == item.key))
{
hashTable[hashCode].Add(item);
if (item.prev != null)
{
item.prev.next = item;
}
return(item);
}
else
{
hashTable[hashCode].Find(i => i.key == item.key).value = item.value;
return(item.prev);
}
}