Question

How to find the first repeating element in an array of integers with Python

Answer 1

def get_first_repeating_element(arr):
    x = -1
    dic = dict()

    for i in range(len(arr) - 1, -1, -1):
        if arr[i] in dic.keys(): 
            x = i
        else: 
            dic[arr[i]] = 1

    if (x != -1):
        return arr[x]

    return 0
    


arr = [1, 2, 4, 5, 6, 5, 4, 3, 7]

n = get_first_repeating_element(arr)

if (n != -1):
    print("First repeating element is:", n)
else:
    print("No repeating elements")
    
    
    
'''
run:

First repeating element is: 4

'''

 

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