Python: Find the first duplicate element in a given array of integers
Python: Array Exercise-15 with Solution
Write a Python program to find the first duplicate element in a given array of integers. Return -1 if there are no such elements.
Sample Solution:
Python Code :
def find_first_duplicate(nums):
num_set = set()
no_duplicate = -1
for i in range(len(nums)):
if nums[i] in num_set:
return nums[i]
else:
num_set.add(nums[i])
return no_duplicate
print(find_first_duplicate([1, 2, 3, 4, 4, 5]))
print(find_first_duplicate([1, 2, 3, 4]))
print(find_first_duplicate([1, 1, 2, 3, 3, 2, 2]))
Sample Output:
4 -1 1
Python Code Editor:
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Previous: Write a Python program to find if a given array of integers contains any duplicate element. Return true if any value appears at least twice in the said array and return false if every element is distinct.
Next: Write a Python program to check whether it follows the sequence given in the patterns array.
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