Submission #2739543

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Source Code Expand

# -*- coding: utf-8 -*-
# AtCoder Beginner Contest


if __name__ == '__main__':
    n = int(input())
    a = list(map(int, input().split()))
    count = 0

    for i in range(len(a)):
        k = a[i] - 1

        if a[i] != -999 and a[k] != -999:
            if (i + 1) == a[k] and (a[i] - 1) == a.index(a[k]):
                count += 1

                a[i] = -999
                a[k] = -999

    print(count)

Submission Info

Judge Result