2460. Apply Operations to an Array

Easy
​
You are given a 0-indexed array nums of size n consisting of non-negative integers.
You need to apply n - 1 operations to this array where, in the ith operation (0-indexed), you will apply the following on the ith element of nums:
  • If nums[i] == nums[i + 1], then multiply nums[i] by 2 and set nums[i + 1] to 0. Otherwise, you skip this operation.
After performing all the operations, shift all the 0's to the end of the array.
  • For example, the array [1,0,2,0,0,1] after shifting all its 0's to the end, is [1,2,1,0,0,0].
Return the resulting array.
Note that the operations are applied sequentially, not all at once.
Example 1:
Input: nums = [1,2,2,1,1,0]
Output:
[1,4,2,0,0,0]
Explanation:
We do the following operations:
- i = 0: nums[0] and nums[1] are not equal, so we skip this operation.
- i = 1: nums[1] and nums[2] are equal, we multiply nums[1] by 2 and change nums[2] to 0. The array becomes [1,4,0,1,1,0].
- i = 2: nums[2] and nums[3] are not equal, so we skip this operation.
- i = 3: nums[3] and nums[4] are equal, we multiply nums[3] by 2 and change nums[4] to 0. The array becomes [1,4,0,2,0,0].
- i = 4: nums[4] and nums[5] are equal, we multiply nums[4] by 2 and change nums[5] to 0. The array becomes [1,4,0,2,0,0].
After that, we shift the 0's to the end, which gives the array [1,4,2,0,0,0].
Example 2:
Input: nums = [0,1]
Output:
[1,0]
Explanation:
No operation can be applied, we just shift the 0 to the end.
Constraints:
  • 2 <= nums.length <= 2000
  • 0 <= nums[i] <= 1000

解題

Runtime: 7 ms, faster than 100%
Memory Usage: 3.2 MB, less than 100%
func applyOperations(nums []int) []int {
length := len(nums)
res := make([]int, 0)
​
for i:=1; i<length; i++ {
if nums[i] == nums[i-1] {
nums[i-1] *= 2
nums[i] = 0
}
}
​
for _, num := range nums {
if num != 0 { res = append(res, num) }
}
​
for _, num := range nums {
if num == 0 { res = append(res, num) }
}
​
return res
}