[HackerRank][Python3] Pairs

Problem :

https://www.hackerrank.com/challenges/pairs/problem

My Solution :

#!/usr/bin/env python3


def pairs(k, arr):
    found = 0
    memo = {}
    for a in sorted(arr):
        if a-k in memo:
            found += 1
        memo[a] = 1
    return found


n, k = map(int, input().split())
arr = list(map(int, input().rstrip().split()))
result = pairs(k, arr)
print(result)

My Solution2 :

#!/usr/bin/env python3


def pairs(k, arr):
    arr.sort()
    found = 0
    i, j = 0, 1
    while j < len(arr):
        if arr[j] - arr[i] == k:
            found += 1
            j += 1
        elif arr[j] - arr[i] < k:
            j += 1
        else:
            i += 1
    return found


n, k = map(int, input().split())
arr = list(map(int, input().rstrip().split()))
result = pairs(k, arr)
print(result)