﻿ Python: Find two elements once in a list where every element appears exactly twice in the list - w3resource

# Python Challenges: Find two elements once in a list where every element appears exactly twice in the list

## Python Challenges - 1: Exercise-15 with Solution

Write a Python program to find two elements once in a list where every element appears exactly twice in the list.

Explanation :

Sample Solution:-

Python Code:

``````import functools
import operator
def two_numbers(arr):
x_xor_y = functools.reduce(operator.xor, arr)
bit =  x_xor_y & -x_xor_y
result = [0, 0]
for i in arr:
result[bool(i & bit)] ^= i
return result

print(two_numbers([1, 2, 1, 3, 2, 5]))
print(two_numbers([11, 5, 3, 7, 0, 5, 3, 6, 7, 11]))
```
```

Sample Output:

```[5, 3]
[0, 6]
```

Flowchart:

Python Code Editor:

```import functools
import operator
def two_numbers(arr):
x_xor_y = functools.reduce(operator.xor, arr)
bit =  x_xor_y & -x_xor_y
result = [0, 0]
for i in arr:
result[bool(i & bit)] ^= i
return result

print(two_numbers([1, 2, 1, 3, 2, 5]))
print(two_numbers([11, 5, 3, 7, 0, 5, 3, 6, 7, 11]))```

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