We have some permutation A
of [0, 1, ..., N - 1]
, where N
is the length of A
.
The number of (global) inversions is the number of i < j
with 0 <= i < j < N
and A[i] > A[j]
.
The number of local inversions is the number of i
with 0 <= i < N
and A[i] > A[i+1]
.
Return true
if and only if the number of global inversions is equal to the number of local inversions.
Example 1:
Input: A = [1,0,2] Output: true Explanation: There is 1 global inversion, and 1 local inversion.
Example 2:
Input: A = [1,2,0] Output: false Explanation: There are 2 global inversions, and 1 local inversion.
Note:
<li><code>A</code> will be a permutation of <code>[0, 1, ..., A.length - 1]</code>.</li>
<li><code>A</code> will have length in range <code>[1, 5000]</code>.</li>
<li>The time limit for this problem has been reduced.</li>