Amazon Student Intern Interview Questions, Process, and Tips

Reversing a linked list involves changing the direction of the pointers in the list.

• Iteratively swap the next and previous pointers of each node in the list

• Recursively reverse the rest of the list and then change the next pointer of the current node

• Use a stack to push each node onto the stack and then pop them off to create the reversed list

Implement a stack with O(1) to get the min value.

• Use two stacks, one for the actual values and one for the minimum values

• Push the new value onto the value stack and compare it with the top of the minimum stack

• If it's smaller or equal, push it onto the minimum stack as well

• When popping a value, check if it's the minimum and pop from the minimum stack if so

Implement array with O(1) setAll to set all values to a given value.

• Create an array of strings with a fixed size.

• Create a variable to store the value to be set.

• When setAll is called, assign the value to the variable.

• When accessing any element of the array, return the value stored in the variable.

• This approach ensures that all elements of the array are set to the same value in constant time.

To find a loop in a linked list, use Floyd's Cycle Detection Algorithm.

• Use two pointers, slow and fast, to traverse the linked list.

• If there is a loop, the fast pointer will eventually meet the slow pointer.

• Once they meet, move one pointer back to the head and start moving both pointers one node at a time until they meet again.