Medium
There is a 0-indexed array nums
of length n
. Initially, all elements are uncolored (has a value of 0
).
You are given a 2D integer array queries
where queries[i] = [indexi, colori]
.
For each query, you color the index indexi
with the color colori
in the array nums
.
Return an array answer
of the same length as queries
where answer[i]
is the number of adjacent elements with the same color after the ith
query.
More formally, answer[i]
is the number of indices j
, such that 0 <= j < n - 1
and nums[j] == nums[j + 1]
and nums[j] != 0
after the ith
query.
Example 1:
Input: n = 4, queries = [[0,2],[1,2],[3,1],[1,1],[2,1]]
Output: [0,1,1,0,2]
Explanation: Initially array nums = [0,0,0,0], where 0 denotes uncolored elements of the array.
Example 2:
Input: n = 1, queries = [[0,100000]]
Output: [0]
Explanation: Initially array nums = [0], where 0 denotes uncolored elements of the array.
Constraints:
1 <= n <= 105
1 <= queries.length <= 105
queries[i].length == 2
0 <= indexi <= n - 1
1 <= colori <= 105
class Solution {
fun colorTheArray(n: Int, queries: Array<IntArray>): IntArray {
val nums = IntArray(n)
val res = IntArray(queries.size)
var count = 0
for ((i, q) in queries.withIndex()) {
val (e, c) = q
if (e > 0 && nums[e] != 0 && nums[e - 1] == nums[e]) count--
if (e < n - 1 && nums[e] != 0 && nums[e + 1] == nums[e]) count--
nums[e] = c
if (e > 0 && nums[e] != 0 && nums[e - 1] == nums[e]) count++
if (e < n - 1 && nums[e] != 0 && nums[e + 1] == nums[e]) count++
res[i] = count
}
return res
}
}