C++示例程序:
class Solution {
public:
int singleNumber(vector<int>& nums) {
int length = nums.size();
if (length == 0 || length == 2)
return 0;
for (int i = 0; i < length - 1; i++) {
nums[0] ^= nums[i + 1];
}
return nums[0];
}
};