Submission #1676543

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Source Code Expand

#!/usr/bin/env python3
# -*- coding: utf-8 -*-



def main():
    N = int(input())
    A = tuple(map(int, input().split()))
    A = tuple(a-1 for a in A) # 0-based

    ans = 0
    for i in range(N):
        b = A[i]
        if A[b] == i:
            ans += 1

    ans //= 2
    print(ans)

if __name__ == "__main__": main()

Submission Info

Judge Result