Problem

Given a list of integers, write a Python function to find the first non-repeating element in the list.
Example input: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
Example output: 1

Solution

def find_first_non_repeating(list):
    
    This function takes a list of integers and returns the first non-repeating element in the list.
    The function uses a dictionary to store the number of times each element appears in the list.
    The function then iterates through the list and returns the first element that appears only once.
    The function is optimal because it only iterates through the list once and uses a dictionary to store the number of times each element appears in the list.
    
    dict = {}
    for i in list:
        if i in dict:
            dict[i] += 1
        else:
            dict[i] = 1
    for i in list:
        if dict[i] == 1:
            return i

print(find_first_non_repeating([1, 2, 3, 4, 5, 6, 7, 8, 9, 10]))