405867: GYM102136 I Permutations again
Memory Limit：256 MB
Time Limit：1 S
Judge Style：Text Compare
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Description
I. Permutations againtime limit per test1 secondmemory limit per test256 megabytesinputstandard inputoutputstandard output1 ≤ N ≤ 106 1 ≤ Ai ≤ N Output
Given a sequence Ai consisting of N integers. Find the number of pairs (L, R) for which the subsegment {AL, AL + 1, ..., AR} is a permutation of R - L + 1 numbers.
A permutation of K numbers is any sequence of numbers from 1 to K, where each element occurs only once.
InputThe first line contains number N — a sequence length. The second line contains N integers — sequence Ai elements.
Print the number of pairs (L, R), fulfilling the condition.
ExampleInput3Output
3 1 2
3