private int GetMax(
SortedDictionary <bool, TrieNode <bool> > nodes,
IntBinary num,
int index)
{
if (index >= num.Count)
{
return(0);
}
var bit = num[index];
var notBit = !bit;
if (nodes.ContainsKey(notBit))
{
var bitValue = Convert.ToInt32(Math.Pow(2, num.Count - index - 1));
return(bitValue
+ GetMax(nodes[notBit].Children, num, index + 1));
}
if (nodes.ContainsKey(bit))
{
return(GetMax(nodes[bit].Children, num, index + 1));
}
return(0);
}
public int FindMaximumXOR(int[] nums)
{
if (nums == null)
{
return(int.MinValue);
}
if (nums.Length <= 1)
{
return(0);
}
var n = nums.Max();
var k = n >= Math.Pow(2, 16) ? 32 : n >= Math.Pow(2, 8) ? 16 : 8;
var trie = new Trie <bool>();
var max = int.MinValue;
foreach (var num in nums)
{
var bin = new IntBinary(num, k);
var numMax = GetMax(trie.Nodes, bin, 0);
if (numMax > max)
{
max = numMax;
}
trie.Add(bin);
}
return(max);
}
