# All pairs

Write a function that takes in an array of integers, which can be both positive and negative, along with a target integer. The function should return all unique pairs of integers from the array that sum up to the target integer.

The inputs are defined as follows:

Return a list of tuples, where each tuple contains a pair of integers that sum up to the target integer.

```
def find_pairs_with_sum(arr: List[int], target: int) -> List[Tuple[int, int]]:
```

pass

**Inputs**The inputs are defined as follows:

- arr: A list of integers containing both positive and negative numbers. The array may have duplicate values.
- target: An integer that we are interested in finding pairs for.

**Output**Return a list of tuples, where each tuple contains a pair of integers that sum up to the target integer.

**Example Tests**- find_pairs_with_sum([3, 4, 2, 5], 7) should return [(3, 4), (2, 5)]
- find_pairs_with_sum([2, 4, 1, 5], 9) should return [(4, 5)]
- find_pairs_with_sum([7, 1, 2, 3, 4, -2], 5) should return [(1, 4), (2, 3), (7, -2)]

## Hint

Make sure that your function returns unique combinations. If the array [2, 3, 4, 6] has assigned number 5, only return (2, 3), not (2, 3), (3, 2)## Answer

```
from typing import List, Tuple, Set
```

def find_pairs_with_sum(arr: List[int], target: int) -> List[Tuple[int, int]]:

# Initialize an empty set to store unique pairs

result_set = set()

# Create a set for quick lookups

complementary_set = set()

# Iterate through the array to find pairs that sum up to the target

for num in arr:

complement = target - num

if complement in complementary_set:

# Sort the pair (smaller, larger) before adding to result set for uniqueness

result_set.add(tuple(sorted((num, complement))))

complementary_set.add(num)

# Convert the set to a list of tuples

return list(result_set)

# Test the function with the given test cases

test_cases = [

([3, 4, 2, 5], 7),

([2, 4, 1, 5], 9),

([7, 1, 2, 3, 4, -2], 5)

]

for arr, target in test_cases:

print(f"find_pairs_with_sum({arr}, {target}) = {find_pairs_with_sum(arr, target)}")