[LeetCode] 136. Single Number 单独数

2021年09月15日 阅读数：1

Given a non-empty array of integers, every element appears twice except for one. Find that single one.html

Note:java

Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory?python

Example 1:数组

```Input: [2,2,1]
Output: 1
```

Example 2:app

```Input: [4,1,2,1,2]
Output: 4```

A B
F F F
F T T
T F T
T T F

Java:blog

```public class Solution {
public int singleNumber(int[] nums) {
int res = 0;
for (int num : nums) res ^= num;
return res;
}
}
```

Python:

```def singleNumber(self, nums):
"""
:type nums: List[int]
:rtype: int
"""
return 2 * sum(set(nums)) - sum(nums)　　```

Python:

```class Solution(object):
def singleNumber(self, nums):
"""
:type nums: List[int]
:rtype: int
"""
res = 0
for num in nums:
res ^= num

return res　　```

Python:

```import operator
from functools import reduce

class Solution:
"""
:type nums: List[int]
:rtype: int
"""
def singleNumber(self, A):
return reduce(operator.xor, A)　　```

C++:

```class Solution {
public:
int singleNumber(vector<int>& nums) {
int res = 0;
for (auto num : nums) res ^= num;
return res;
}
};
```

[LeetCode] 260. Single Number III 单独数 III