Sigmoid Interview Questions and Answers for Freshers

To detect the best day to buy and sell stock in an integer array representing stock prices and days in O(N).

• Iterate through the array and keep track of the minimum price seen so far.

• Calculate the profit by subtracting the current price from the minimum price.

• Update the maximum profit and best buy/sell days accordingly.

• Return the best buy and sell days to maximize profit.

Bean annotation is used in Spring Boot on class or method to indicate that a method produces a bean to be managed by the Spring container.

• Bean annotation is used on methods within a class to indicate that the method produces a bean to be managed by the Spring container.

• It can also be used at the class level to indicate that the class itself is a Spring bean.

• For example, @Bean annotation can be used on a method that creates and returns a DataSource bean in a configuration clas...read more

Protected access modifier restricts interface method access to only derived or implemented classes.

• Use 'protected' access modifier to restrict access to only derived or implemented classes

• Protected members are accessible within the same package or by subclasses

• Example: 'protected void methodName() {}' in an interface

Microservices interact with each other through APIs, messaging, or events.

• Microservices communicate with each other through APIs, which can be synchronous or asynchronous.

• Messaging systems like RabbitMQ or Kafka can be used for communication between microservices.

• Events can be used for loosely coupled communication between microservices.

• Service discovery mechanisms like Eureka or Consul help microservices locate and communicate with each other.

• API gateways can be used to mana...read more

Using a stack to find the next greater element in an array of strings.

• Iterate through the array from right to left.

• Push elements onto the stack and compare with the top element to find the next greater element.

• Pop elements from the stack until a greater element is found or stack is empty.

Check for a loop in a linked list by using two pointers moving at different speeds.

• Use two pointers, one moving at a normal speed and another moving at double the speed.

• If there is a loop, the two pointers will eventually meet at some point.

• Alternatively, use a hash set to store visited nodes and check for duplicates.

Find the next greatest number for each integer in an array in O(N) time complexity.

• Iterate through the array from right to left

• Use a stack to keep track of potential next greatest numbers

• Pop elements from the stack that are less than the current element and update their next greatest number to the current element

• Push the current element onto the stack

• Repeat until all elements have a next greatest number

Python program to count vowels in a given string

• Iterate through the string and check if each character is a vowel (a, e, i, o, u)

• Increment a counter for each vowel found

• Return the total count of vowels