def contains_duplicate(nums):
    records = {}
    for i in nums:
        if i in records:
            return True
        
        records[i] = i
    return False

# driver code
def main():
    arrays = [[1, 2, -3, 2, 1], [2, 5, 7, 9], [5, 6, 4, 7, 6, 11], [1, 4, 6, 10, 18, -2, -4], [3, 4, 8, 20, 34, 89, 3]]
    for i in range(len(arrays)):
        result = contains_duplicate(arrays[i])
        print(str(i+1)+".\tDoes the given array", arrays[i], "contains duplicates?", result)
        print("-"*100)

if __name__ == '__main__':
    main()