How to pass the Oracle Coding interview? Real high-frequency questions + complete problem-solving ideas

Just completed one recently Oracle Coding interview, the overall experience was not bad. What makes me more satisfied is that the performance in each round was relatively stable and there were no obvious mistakes. The successful passage this time was indeed inseparable from the help of Programhelp. So, I also want to share this interview experience and some real questions I compiled to serve as a reference for students preparing for Oracle Coding interviews later.

Oracle Coding Interview Process Overview

Oracle real coding interview questions

Question 1: Ratan’s stock profits

Problem description:

Ratan is a super rich man, and he is extremely lucky and always buys and sells stocks in the optimal way to get the maximum profit. He always buys stocks at the lowest price and sells them at the highest price, thus maximizing profits.

Now you are the tax officer and need to calculate the maximum profit made by Ratan based on the daily stock price. You just need to calculate the maximum profit he can make from a single trade (one buy + one sell).

Notice:

• Ratan never loses money (i.e. If it cannot make a profit, the profit is 0 and no trade is made).

Example 1: Price = [1, 6, 2] Ratan buys for 1 yuan on the first day and sells for 6 yuan on the second day, with a maximum profit of 5.

Example 2: Price = [9, 8, 6] The stock price keeps falling, Ratan does not buy, and the maximum profit is 0.

Input format: The first line is an integer n, representing the total number of days (the number of days the stock has been in stock). Next n lines, each line contains an integer, representing the price of the stock on that day.

Output format: Output an integer on a single line representing the maximum profit made by Ratan.

Constraints:

• 1 ≤ n ≤ 10⁸ (the number of days is up to 100 million, need to pay attention to time and space complexity)

Sample input (custom test):

Text

7
1
9
2
11
1
9
2

Sample output:

Text

10

Explain: The maximum profit is to buy when the price is 1 (day 1 or 5) and sell when the price is 11 (day 4), profit = 11 – 1 = 10.

Code reference

Def func(diff):
    n=len(diff)
    if n==0:
        return 0
    mx=max(diff)
    if mx <= 0:
        return 0
    mxS=0
    cS=0
    for i in diff:
        cS+=i
        if cS <= 0:
            cS=0
        mxS=max(cS,mxS)
    return mxS

n=int(input())
arr=[]
diff=[]
ans=[0]
for i in range(n):
    arr.append(int(input()))c++
for i in range(n-1):
    diff.append(arr[i+1]-arr[i])
ans=func(diff)
if ans < 0:
    print("0")
else:
    print(ans)

Question 2: Bank loan comparison

Problem description:

There are two banks - Bank A and Bank B, and they have different interest rates. You receive loan quotes from two banks, including the annual interest rate, the loan term in years, and how the interest rate will change over the entire term.

You must choose the loan option with the lowest total interest cost and reject the other one. Please do the math and make an informed choice.

The loan is repaid with monthly frequency and the Equal Monthly Installment (EMI) is calculated using the following formula:

EMI = loanAmount × monthlyInterestRate / (1 – 1 / (1 + monthlyInterestRate)^(numberOfYears × 12))

In:

• MonthlyInterestRate = annual interest rate / 12 / 100
• NumberOfYears is the number of years corresponding to the current interest rate segment (slab)

Constraints:

• 1 ≤ P (principal) ≤ 1,000,000
• 1 ≤ T (total years) ≤ 50
• 1 ≤ N1 (number of Bank A segments) ≤ 30
• 1 ≤ N2 (number of Bank B segments) ≤ 30

Input format:

• The first line: P (Principal Loan Amount)
• Second line: T (total term, total number of years)
• The third row: N1 (the number of interest rate segments of Bank A)
• Next line N1: two numbers in each line - number of years and annual interest rate (for example: 5 9.5 means that this segment lasts for 5 years and the annual interest rate is 9.5%)
• Next row: N2 (Bank B’s number of interest rate segments)
• Next N2 lines: two numbers per line - number of years annual interest rate

Notice: Segments begin in year 1 and are accumulated sequentially, with subsequent segments beginning in the year following the end of the previous segment.

Output format:

Output a line representing the bank you selected:Bank A Or Bank B(Choose the bank with the lower total payment amount).

Example 1

Enter:

Text

10000
20
3
5 9.5
10 9.6
5 8.5
3
10 6.9
5 8.5
5 7.9

Output:

Text

Bank B

Example 2

Enter:

Text

500000
26
3
13 9.5
3 6.9
10 5.6
3
14 8.5
6 7.4
6 9.6

Output:

Text

Bank A

Code reference

Bank = []
principal = int(input())
year = int(input()
for i in range(0, 2): # 2 Banks
    installments = int(input())
    sum = 0
    for i in range(0, installments):
        time, roi = [float(i) for i in input().split()]
        square = pow((1+roi), time*12)
        emi = (principal*(roi)/(1-1/square))
        sum = sum + emi
    bank.append(sum)
if bank[0] < bank[1]:
    print("Bank A")
else:
    print("Bank B")
Output:
10000
20
3
5 9.5
10 9.6
5 8.5
3
10 6.9
5 8.5
5 7.9
Bank B

Issue 3: Network Flow

Problem description:

There is a containing N A stream of packets arrives at the server. The server can only handle packets of size exactly 2ⁿ units (units), where n is a nonnegative integer (0 ≤ n).

All packets are sequentially repackaged to the currently largest possible 2ⁿ size. The remainder after packaging is added to the next arriving packet and then repackaged.

Find the maximum repackaged packet size in a given packet flow.

Example: Arrival packets = [12, 25, 10, 7, 8]

• The first packet has 12 units. The largest 2ⁿ that can be packed is 2³ = 8 (because the next 2⁴ = 16 is larger than 12). The remaining 12 – 8 = 4 units are accumulated to the next packet.
• The next packet becomes 4 + 25 = 29 units, the maximum 2ⁿ that can be packed is 2⁴ = 16, leaving 29 – 16 = 9 units.
• The next one becomes 9 + 10 = 19 units, the maximum 2ⁿ that can be packed is 16, leaving 19 – 16 = 3 units.
• The next one becomes 3 + 7 = 10 units, the maximum 2ⁿ that can be packed is 8, leaving 10 – 8 = 2 units.
• The last one becomes 2 + 8 = 10 units, and the maximum 2ⁿ that can be packed is 8.

The maximum size after repacking is 16 Units.

Return: Type long – The maximum repackaged packet size in the stream.

Constraints:

• 1 ≤ n ≤ 10⁵
• 1 ≤ arrivingPackets[i] ≤ 10⁹

Sample input 0:

Text

5
13
25
12
2
8

Sample output 0:

Text

16

Reference code

Def largeRepackagedPacket(arr):
    twoP = [int(2**i) for i in range(31)]
    x = 0
    ans = 0
    for i in arr:
        i = i + x
        for j in range(31):
            if i < twoP[j]:
                break
        x = i - twoP[j - 1]
        if ans <= twoP[j - 1]:
            ans = twoP[j - 1]
    return ans


Packets = []
for i in range(int(input())):
    Packets.append(int(input()))
print(largeRepackagedPacket(Packets))

How to prepare effectively for Oracle Coding interview?

HackerRank official resources:
Highly recommended as a preferred practice platform. Many of Oracle's OA and part of the interview coding sessions are conducted on this platform, so it is very important to be familiar with the interface and submission process in advance.

Interview and experience summary:
In addition to answering questions, it is also very important to understand the real interview process and high-frequency test points in advance. Programhelp has compiled a large number of interview experiences based on past auxiliary cases, which can make it clearer what types of questions Oracle often takes and what points the interviewer focuses on.

For example:

• Oracle 26NG SDE full process review
• Oracle Health SDE interview experience | Programhelp student real experience 

LeetCode additional exercises:
Suitable as a daily question-answering platform to improve the feel. The question bank has very comprehensive coverage and has company tags, so you can focus on questions related to Oracle/big companies.

It is recommended to focus on:

• Double pointer (such as Container With Most Water)
• Linked list (LRU Cache)
• Heap/Priority Queue (Merge K Lists)
• Recursion of tree (deleting leaf node class problem)

VO interview assistance
If you have entered the VO stage, many students will actually find:
The problem is not "not being able to write", but time pressure + expression + on-the-spot thinking breakdown. ProgramHelp VO interview assistance uses real-time prompts and idea guidance from North American CS experts to help you express clearly and respond to follow-ups, greatly improving the pass rate. It is especially suitable for students who are stable in answering questions but unstable in actual practice.

Jory Wang Amazon Senior Software Development Engineer

Amazon senior engineer, focusing on the research and development of infrastructure core systems, with rich practical experience in system scalability, reliability and cost optimization. Currently focusing on FAANG SDE interview coaching, helping 30+ candidates successfully obtain L5/L6 Offers within one year.

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