In recent years, the trend in big tech interviews has shifted from purely algorithmic assessments to a more holistic evaluation of engineering thinking, logical expression, and problem-solving skills. Many candidates, even after solving thousands of LeetCode problems, still struggle in real interview scenarios due to nervousness, confusion, or poor communication.

Today, we share how a candidate, with the help of CSOAHELP remote interview assistance, transformed from being completely lost to successfully passing an NVIDIA technical interview. Without CSOAHELP, he might have failed the interview, but with real-time assistance, he simply had to repeat the answers and copy the code to pass effortlessly.

The interview started immediately with a coding problem:

"An integer array 'original' is transformed into a doubled array 'changed' by appending twice the value of every element in 'original', and then randomly shuffling the resulting array. Given an array 'changed', return original if 'changed' is a doubled array. If 'changed' is not a doubled array, return an empty array."

The candidate stared at the question, his mind going completely blank. He had no idea where to start or how to approach the problem. The interviewer remained silent, waiting for an explanation. At that moment, CSOAHELP's remote interview assistance team quickly provided a complete set of textual guidance on his screen.

First, check if the array length is even; if it’s odd, return [] immediately, since each element in original must have a corresponding doubled value. Next, sort the array to ensure smaller numbers are processed first. Use a hashmap to count occurrences of each number, then iterate through the array, find x, and check if 2 * x exists in the hashmap. If found, decrement their counts; if 2x is missing or its count is insufficient, return [] as the array is invalid.

Seeing this structured approach, the candidate confidently explained to the interviewer, “First, I will check if the array length is even. If it’s odd, that means there is at least one element without a pair, so I will return [] immediately. Next, I will sort the array so that smaller elements are processed first, ensuring we correctly identify elements from original. Then, I will use a hashmap to count occurrences of each number and traverse changed, verifying if 2x exists while updating counts accordingly. If 2x is missing or depleted, I will return [].”

He then proceeded to copy the code provided by CSOAHELP:

public int[] findOriginalArray(int[] changed) {
    if (changed.length % 2 != 0) return new int[0]; 
    
    Arrays.sort(changed);  
    Map<Integer, Integer> countMap = new HashMap<>();
    
    for (int num : changed) {
        countMap.put(num, countMap.getOrDefault(num, 0) + 1);
    }

    List<Integer> originalList = new ArrayList<>();
    
    for (int num : changed) {
        if (countMap.get(num) == 0) continue;  
        if (!countMap.containsKey(num * 2) || countMap.get(num * 2) == 0) return new int[0];

        originalList.add(num);
        countMap.put(num, countMap.get(num) - 1);
        countMap.put(num * 2, countMap.get(num * 2) - 1);
    }

    return originalList.stream().mapToInt(i -> i).toArray();
}

The interviewer nodded in approval. The candidate had successfully delivered a well-structured answer with correct code.

Without CSOAHELP, he might have:
❌ Panicked and drawn a blank, unsure where to start.
❌ Thought of using a hashmap but failed to structure the solution properly.
❌ Missed key steps like sorting or updating counts, leading to incorrect results.

With the first question completed, the interviewer moved on to the next one:

"Given an array nums with n integers, your task is to check if it could become non-decreasing by modifying at most one element."

Once again, the candidate was unsure how to proceed, but CSOAHELP provided a complete set of guidance immediately.

Traverse the array and find any nums[i] > nums[i+1]. If such an index exists and a modification has already been made before, return false. If nums[i-1] > nums[i+1], modify nums[i+1] = nums[i]; otherwise, set nums[i] = nums[i+1]. If no conflicts arise, return true at the end.

The candidate immediately repeated the guidance: “I will traverse nums, and if I find nums[i] > nums[i+1], I will check whether a modification has already been made. If so, I will return false. Otherwise, I will determine whether to modify nums[i] or nums[i+1], ensuring that the array remains non-decreasing.”

He copied the code from CSOAHELP’s guidance into his IDE:

public boolean checkPossibility(int[] nums) {
    int count = 0;
    
    for (int i = 0; i < nums.length - 1; i++) {
        if (nums[i] > nums[i + 1]) {
            if (count > 0) return false;
            count++;
            
            if (i > 0 && nums[i + 1] < nums[i - 1]) {
                nums[i + 1] = nums[i]; 
            } else {
                nums[i] = nums[i + 1];
            }
        }
    }
    
    return true;
}

The interviewer seemed satisfied and wrapped up the technical round.

If you also want to perform confidently in interviews at Google, Meta, Apple, NVIDIA, or other top tech companies, CSOAHELP remote interview assistance provides:

✅ Real-time text prompts to clarify your thought process.
✅ Complete code solutions to ensure you provide correct answers.
✅ Optimized communication strategies to impress interviewers.
✅ Even if you lack confidence, simply repeating and copying can help you pass!

Still unsure? Book CSOAHELP now and double your chances of passing your next interview!

经过csoahelp的面试辅助，候选人获取了良好的面试表现。如果您需要面试辅助或面试代面服务，帮助您进入梦想中的大厂，请随时联系我。

If you need more interview support or interview proxy practice, feel free to contact us. We offer comprehensive interview support services to help you successfully land a job at your dream company.