90 lines
2.0 KiB
C++
90 lines
2.0 KiB
C++
class Trie {
|
|
public:
|
|
struct Node
|
|
{
|
|
bool ends;
|
|
int number;
|
|
Node* next[2];
|
|
|
|
Node()
|
|
{
|
|
ends = false;
|
|
memset(next, 0, sizeof(next));
|
|
}
|
|
};
|
|
Node* root;
|
|
|
|
Trie() {
|
|
root = new Node;
|
|
}
|
|
|
|
inline void stepDownInsert(int* bits, int leftBits, int number, Node* current) {
|
|
if (!leftBits) {
|
|
current->ends = true;
|
|
current->number = number;
|
|
return;
|
|
}
|
|
|
|
if (!current->next[bits[leftBits - 1]]) {
|
|
auto n = new Node;
|
|
current->next[bits[leftBits - 1]] = n;
|
|
}
|
|
stepDownInsert(bits, leftBits - 1, number, current->next[bits[leftBits - 1]]);
|
|
}
|
|
|
|
void insert(int number) {
|
|
int bits[32] = { 0 };
|
|
int input = number;
|
|
int index = 0;
|
|
while (input) {
|
|
bits[index++] = input & 0x1;
|
|
input >>= 1;
|
|
}
|
|
stepDownInsert(bits, 31, number, root);
|
|
}
|
|
};
|
|
|
|
class Solution {
|
|
public:
|
|
Trie t;
|
|
|
|
int findMaximumXOR(vector<int>& nums) {
|
|
for (auto& n : nums) {
|
|
t.insert(n);
|
|
}
|
|
|
|
int maxResult = 0;
|
|
|
|
for (auto& n : nums) {
|
|
int bits[32] = { 0 };
|
|
int input = n;
|
|
int index = 0;
|
|
while (input) {
|
|
bits[index++] = input & 0x1;
|
|
input >>= 1;
|
|
}
|
|
|
|
auto current = t.root;
|
|
int result = 0;
|
|
for (int i = 30; i >= 0; i--) {
|
|
result <<= 1;
|
|
if (bits[i] && current->next[0]) {
|
|
current = current->next[0];
|
|
result++;
|
|
}
|
|
else if (!bits[i] && current->next[1]) {
|
|
current = current->next[1];
|
|
result++;
|
|
}
|
|
else {
|
|
current = current->next[0] ? current->next[0] : current->next[1];
|
|
}
|
|
}
|
|
|
|
maxResult = max(maxResult, result);
|
|
}
|
|
|
|
return maxResult;
|
|
}
|
|
};
|