Problem Explanation
The task is to find all pairs of integers from a list of n
pairs where the sum of the elements in each pair is divisible by a given integer k
. The order of pairs in the output should match the order in which they were provided in the input.
Approach
To find and print all pairs of integers from a list where the sum of each pair is divisible by a given integer k
, we first read the number of pairs n
and the integer k
, then store the pairs in a vector. We iterate through each pair, calculate the sum of the two integers, and check if the sum is divisible by k
. If it is, we print the pair, ensuring that the output order matches the input order. This approach efficiently processes each pair in O(n) time.
Complexity Analysis

Time Complexity: The time complexity is O(n), where
n
is the number of pairs. This is because the program iterates through each pair once to check if the sum is divisible byk
. 
Space Complexity: The space complexity is O(n) due to the storage of the pairs in a vector, or if O(1) if we donâ€™t consider the input storage space.