Pair Sum Problem Statement

You are given an integer array 'ARR' of size 'N' and an integer 'S'. Your task is to find and return a list of all pairs of elements where each sum of a pair equals 'S'.

Note:

Each pair should be ordered such that the first value is less than or equal to the second value. The list of pairs should be sorted in non-decreasing order based on their first values. If two pairs have the same first value, the pair with the smaller second value should come first.

Input:

N S ARR[0] ARR[1] ... ARR[N-1]

Output:

C x1 y1 x2 y2 ...

Example:

Input:

N = 5, S = 7 ARR = [3, 1, 2, 4, 5]

Output:

[2, 5] [3, 4]

Constraints:

1 ≤ N ≤ 10³

-10⁵ ≤ ARR[i] ≤ 10⁵

-2 * 10⁵ ≤ S ≤ 2 * 10⁵

Time Limit: 1 sec

Note:

You don't need to print the output; just implement the logic to return the required result.

Question

Pair Sum Problem Statement

You are given an integer array 'ARR' of size 'N' and an integer 'S'. Your task is to find and return a list of all pairs of elements where each sum of a pair equals 'S'.

Note:

Each pair should be ordered such that the first value is less than or equal to the second value. The list of pairs should be sorted in non-decreasing order based on their first values. If two pairs have the same first value, the pair with the smaller second value should come first.

Input:

N S
ARR[0] ARR[1] ... ARR[N-1]

Output:

C
x1 y1
x2 y2
...

Example:

Input:

N = 5, S = 7
ARR = [3, 1, 2, 4, 5]

Output:

[2, 5]
[3, 4]

Constraints:

1 ≤ N ≤ 10³
-10⁵ ≤ ARR[i] ≤ 10⁵
-2 * 10⁵ ≤ S ≤ 2 * 10⁵

Time Limit: 1 sec

Note:

You don't need to print the output; just implement the logic to return the required result.

Accepted Answer

Find pairs of elements in an array that sum up to a given value, sorted in a specific order.

Iterate through the array and for each element, check if the complement (S - current element) exists in a hash set.
Keep track of pairs in a hash set to avoid duplicates.
Sort the pairs based on the criteria mentioned in the problem statement.
Return the sorted list of pairs.

Accepted Answer

s=7
a=[3,1,2,4,5]
res=[]
for i in a:
    if((s-i) in a and ([i,s-i] not in res and [s-i,i] not in res)):
        res.append([i,s-i])
for i in res:
    print(i)