Find if sum a of pair of integer exists in an array

search_sum_of_pair_in_array.py

def brute_force(arr, s):
    for i in arr:
        for j in arr:
            if i + j == s:
                print("{} + {} = {}".format(i, j, s))


# brute_force([5, 3, 7, 0, 1, 4, 2], 5)


def binary_search(arr, s):
    left = 0
    right = len(arr) - 1
    while True:
        if left > right:
            return None
        m = (left + right) // 2
        e = arr[m]
        if e < s:
            left = m + 1
        elif e > s:
            right = m - 1
        else:
            return m


def n_log_n(arr, s):
    for e in arr:
        i = binary_search(arr, s - e)
        if i is not None:
            print("{} + {} = {}".format(i, e, s))


# n_log_n([0, 1, 2, 3, 4, 5, 7], 5)

def n(arr, s):
    d = {}
    for e in arr:
        d[e] = e

    for i, e in enumerate(arr):
        t = s - e
        if t in d and d[t] != i:
            print("{} + {} = {}".format(d[t], e, s))


n([5, 3, 7, 0, 1, 4, 2], 5)