Redaksiya

Let $p$ be a given permutation. Its application means moving an element from position $i$ to position $p_i$, i.e., the transformation $i\to p_i$ occurs. The inverse permutation of $p$, denoted as $pi$, will have the inverse transformation where $p_i\to i$ takes place. In other words, in the array $pi$, the number $i$ should be placed at position $p_i(pi[p_i]=i)$.

Example

Consider the permutation $p=\left(\begin{array}{ccc}1& 2& 3\\ 2& 3& 1\end{array}\right)$ and its inverse $p^{-1}=\left(\begin{array}{ccc}1& 2& 3\\ 3& 1& 2\end{array}\right)$. In the inverse permutation the edges are oriented in the opposite direction.

Algorithm realization

The array $p$ stores the input permutation, and the array $pi$ stores the inverse permutation.

#define MAX 20010
int p[MAX], pi[MAX];

Read the input permutation.

scanf("%d",&n);
for(i = 1; i <= n; i++)
  scanf("%d",&p[i]);

Compute the inverse permutation.

for(i = 1; i <= n; i++)
  pi[p[i]] = i;

Print the inverse permutation.

for(i = 1; i <= n; i++)
  printf("%d ",pi[i]);
printf("\n");

Python realization

The list $p$ stores the input permutation, and the list $pi$ stores the inverse permutation. Read the input data.

n = int(input())
p = [0] + list(map(int, input().split()))
pi = [0] * (n + 1)

Compute the inverse permutation.

for i in range(1, n + 1):
  pi[p[i]] = i

Print the inverse permutation.

for i in range(1, n + 1):
  print(pi[i], end=" ")
print()