Apply Operations to an Array | Leetcode 2460

class Solution {
public:
    vector<int> applyOperations(vector<int>& nums) {
        //Apply operations and maintain non-zero operations on the left side
        int n=nums.size();
        int non_zero_idx=0;

        for(int i=0;i<n;++i){
            if(i<n-1 and nums[i]==nums[i+1]){
                nums[i]*=2;
                nums[i+1]=0;
            }
            if(nums[i]!=0)
                swap(nums[i],nums[non_zero_idx++]);
        }
        return nums;
    }
};
/*
//JAVA
import java.util.Arrays;

class Solution {
    public int[] applyOperations(int[] nums) {
        int n = nums.length;
        int nonZeroIdx = 0;

        // Apply operations
        for (int i = 0; i < n; ++i) {
            if (i < n - 1 && nums[i] == nums[i + 1]) {
                nums[i] *= 2;
                nums[i + 1] = 0;
            }
            if (nums[i] != 0) {
                int temp = nums[i];
                nums[i] = nums[nonZeroIdx];
                nums[nonZeroIdx] = temp;
                nonZeroIdx++;
            }
        }
        return nums;
    }

    public static void main(String[] args) {
        Solution sol = new Solution();
        int[] nums = {1, 2, 2, 0, 3, 0, 4};
        int[] result = sol.applyOperations(nums);
        System.out.println(Arrays.toString(result)); // Output: [1, 4, 3, 4, 0, 0, 0]
    }
}

#Python
from typing import List

class Solution:
    def applyOperations(self, nums: List[int]) -> List[int]:
        n = len(nums)
        non_zero_idx = 0

        # Apply operations
        for i in range(n):
            if i < n - 1 and nums[i] == nums[i + 1]:
                nums[i] *= 2
                nums[i + 1] = 0
            if nums[i] != 0:
                nums[i], nums[non_zero_idx] = nums[non_zero_idx], nums[i]
                non_zero_idx += 1

        return nums

# Example usage
sol = Solution()
nums = [1, 2, 2, 0, 3, 0, 4]
result = sol.applyOperations(nums)
print(result)  # Output: [1, 4, 3, 4, 0, 0, 0]
*/