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You have N
bulbs in a row numbered from 1
to N
. Initially, all the bulbs are turned off. We turn on exactly one bulb everyday until all bulbs are on after N
days.
You are given an array bulbs
of length N
where bulbs[i] = x
means that on the (i+1)th
day, we will turn on the bulb at position x
where i
is 0-indexed
and x
is 1-indexed.
Given an integer K
, find out the minimum day number such that there exists two turned on bulbs that have exactly K
bulbs between them that are all turned off.
If there isn't such day, return -1
.
Example 1:
Input:
bulbs: [1,3,2]
K: 1
Output: 2
Explanation:
On the first day: bulbs[0] = 1, first bulb is turned on: [1,0,0]
On the second day: bulbs[1] = 3, third bulb is turned on: [1,0,1]
On the third day: bulbs[2] = 2, second bulb is turned on: [1,1,1]
We return 2 because on the second day, there were two on bulbs with one off bulb between them.
Example 2:
Input:
bulbs: [1,2,3]
K: 1
Output: -1
Note:
1 <= N <= 20000
1 <= bulbs[i] <= N
bulbs
is a permutation of numbers from 1
to N
.
0 <= K <= 20000
[Ordered Map]