public int Sum(string prefix)
{
//GetPrefix Node
MapSumTrieNode prefixNode = MapSumTrie.GetPrefixNode(prefix);
//Get sum of all leaves.
return(MapSumHelper(prefixNode));
}
public MapSumTrieNode GetPrefixNode(string prefix)
{
MapSumTrieNode current = root;
for (int i = 0; i < prefix.Length; i++)
{
if (current.trieNodes[prefix[i] - 'a'] == null)
{
return(null);
}
current = current.Next(prefix[i]);
}
return(current);
}
private int MapSumHelper(MapSumTrieNode node)
{
if (node == null)
{
return(0);
}
int sum = node.sum;
foreach (MapSumTrieNode childNode in node.trieNodes)
{
sum += MapSumHelper(childNode);
}
return(sum);
}
public void Insert(string key, int val)
{
MapSumTrieNode current = root;
for (int i = 0; i < key.Length; i++)
{
if (current.trieNodes[key[i] - 'a'] == null)
{
current.trieNodes[key[i] - 'a'] = new MapSumTrieNode();
}
current = current.Next(key[i]);
}
current.word = key;
current.sum = val;
}
public MapSumTrie()
{
root = new MapSumTrieNode();
}