文章作者：Tyan
博客：noahsnail.com | CSDN | 简书
1. Description
Maximum XOR of Two Numbers in an Array
2. Solution
- Version 1
class Solution {
public:
int findMaximumXOR(vector<int>& nums) {
int max = 0;
int current = 0;
for(int i = 0; i < nums.size(); i++) {
for(int j = i + 1; j < nums.size(); j++) {
current = nums[i] ^ nums[j];
if(current > max) {
max = current;
}
}
}
return max;
}
};
- Version 2
class Solution {
public:
int findMaximumXOR(vector<int>& nums) {
int max = 0;
int mask = 0;
unordered_set<int> s;
for(int i = 30; i >= 0; i--) {
mask = mask | (1 << i);
for(int value : nums) {
s.insert(mask & value);
}
int candidate = max | (1 << i);
for(int value : s) {
if(s.count(candidate ^ value)) {
max = candidate;
break;
}
}
s.clear();
}
return max;
}
};
