{
  "id": 2551,
  "name": "apply-operations-to-an-array",
  "difficulty": "Easy",
  "link": "https://leetcode.com/problems/apply-operations-to-an-array/",
  "date": "2022-10-30",
  "task_description": "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`",
  "test_case": [
    {
      "label": "Example 1",
      "input": "nums = [1,2,2,1,1,0]",
      "output": "[1,4,2,0,0,0] "
    },
    {
      "label": "Example 2",
      "input": "nums = [0,1]",
      "output": "[1,0] "
    }
  ],
  "constraints": [
    "If nums[i] == nums[i + 1], then multiply nums[i] by 2 and set nums[i + 1] to 0. Otherwise, you skip this operation.",
    "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].",
    "2 <= nums.length <= 2000",
    "0 <= nums[i] <= 1000"
  ],
  "python_template": "class Solution(object):\n    def applyOperations(self, nums):\n        \"\"\"\n        :type nums: List[int]\n        :rtype: List[int]\n        \"\"\"\n        ",
  "java_template": "class Solution {\n    public int[] applyOperations(int[] nums) {\n        \n    }\n}",
  "metadata": {
    "func_name": "applyOperations"
  }
}