Minimum swaps needs to sort the array

minimum_swaps.py

class Solution(object):

    def solution(self, a):

        seen = {}

        cycles = []

        for i, n in enumerate(a):

            if n == i:
                continue
            else:
                if seen.get(n) is None:
                    cycle = 1
                    cur = n
                    seen[cur] = True
                    while seen.get(a[cur]) is None:
                        cur = a[cur]
                        cycle += 1
                        seen[cur] = True
                    cycles.append(cycle)

        return sum(cycles) - len(cycles)


if __name__ == "__main__":
    A = [0, 1, 2, 5, 4, 3]
    ans = Solution().solution(A)
    print(ans)