American Express
10+ ROLLING MILL Interview Questions and Answers
Q1. Sliding Window Maximum Problem Statement
You are given an array/list of integers with length 'N'. A sliding window of size 'K' moves from the start to the end of the array. For each of the 'N'-'K'+1 possible wi...read more
The problem involves finding the maximum element in each sliding window of size 'K' in an array of integers.
Iterate through the array and maintain a deque to store the indices of elements in the current window.
Remove indices from the deque that are outside the current window.
Keep the deque in decreasing order of element values to easily find the maximum element in each window.
Explaining a complex joins problem in DBMS
Discussing the use of different types of joins like inner join, outer join, self join, etc.
Explaining how to handle null values and duplicates during joins
Demonstrating a scenario where multiple tables need to be joined based on different keys
Q3. Q1. Case study for Number of Green T-shirts sold in US?
A case study on the number of green T-shirts sold in the US.
Identify the target audience for green T-shirts
Analyze the market demand for green T-shirts
Study the sales data of green T-shirts in the US
Identify the popular brands and styles of green T-shirts
Analyze the impact of seasonality on sales
Consider the pricing strategy of green T-shirts
Identify potential marketing opportunities to increase sales
Q4. How would you decide if a person can be a customer of a private jet company
To determine if a person can be a customer of a private jet company, factors such as income level, travel frequency, and location must be considered.
Consider the individual's income level to determine if they can afford private jet services
Evaluate the person's travel frequency to see if they would benefit from the convenience of private jet travel
Take into account the person's location and travel destinations to assess the need for private jet services
Q5. SQL Query of case when then statement
SQL query using CASE WHEN THEN statement
Use CASE WHEN statement to create conditional logic in SQL queries
Syntax: SELECT column_name, CASE WHEN condition1 THEN result1 WHEN condition2 THEN result2 ELSE result3 END AS new_column_name FROM table_name
Example: SELECT name, CASE WHEN age < 18 THEN 'Minor' ELSE 'Adult' END AS age_group FROM customers
Q6. Factors to account for ATM placements in city?
Factors such as foot traffic, proximity to banks, crime rates, and demographics should be considered for ATM placements in a city.
Foot traffic in the area
Proximity to banks or financial institutions
Crime rates in the neighborhood
Demographics of the area (income levels, age groups)
Accessibility and visibility of the location
Local regulations and zoning laws
Availability of power and network connections
Competition from other ATMs or financial services
Potential for growth and dev...read more
Q7. What is p value?
A p-value is a measure used in statistical hypothesis testing to determine the strength of evidence against the null hypothesis.
A p-value is the probability of obtaining results as extreme as the observed results, assuming the null hypothesis is true.
A p-value is compared to a significance level (usually 0.05) to determine if the null hypothesis should be rejected.
A p-value less than the significance level indicates strong evidence against the null hypothesis.
Q8. difference between append() and concat
append() adds elements to a single DataFrame, while concat() combines multiple DataFrames.
append() is a method used to add rows to a DataFrame.
concat() is a function used to combine multiple DataFrames along a particular axis.
append() modifies the original DataFrame, while concat() returns a new DataFrame.
Example: df1.append(df2) vs pd.concat([df1, df2])
Q9. tell the output a**2
The output of a**2 is the square of the value of a.
The output is the value of a multiplied by itself
For example, if a = 3, then the output would be 9 (3*3)
Q10. SQL Query of join
SQL query to join tables based on a common key
Use JOIN keyword to combine rows from two or more tables based on a related column between them
Specify the columns to be joined in the ON clause
Types of joins include INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN
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