PayPal Software Engineer interview questions

ALGORITHM (weight: 30%) A small directory is hard-coded as an array in the code: String names[] = { "Elon Musk", "Ken Howery", "Luke Nosek", "Max Levchin", "Peter Thiel" }; A requirement is to be able to extend this directory dynamically at runtime, without persistent storage. The directory can eventually grow to hundreds or thousands of names and must be searchable by first or last name. 1) What approach would you take? (Ans: HashMap) 2) Write an implementation for the add and search methods in pseudo-code using data structures you have in mind.

SQL (weight: 10%) Consider the table below: table A ( id integer primary key, name varchar(20), age integer ) Write a query to return the list of unique names from table A

CODING (weight: 50%) The string "PAYPAL IS HIRING" is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font for better legibility) P A H N A P L S I I G Y I R And then read line by line: PAHNAPLSIIGYIR Write the code that will take a string and make this conversion given a number of rows: String convert(String text, int nRows); convert("paypalishiring", 3) should return "pahnaplsiigyir"

Consider the following function: int f (int num) { int out = 0; for (; num > 0; num /= 10) { int d = num % 10; out *= 10; out += d; } return out; } 1) What does it do? 2) Write the same algorithm using recursion

We have the following schema of a table: create table Test (id number, name varchar2(32), desc varchar2(400)); create index index_test on Test (name); Which of the following statements will invoke an index scan by oracle execution plan a) select * from test where name='name'; b) select * from test where name like 'name%'; c) select * from test where name like '%name'; d) select * from test where name like '%name%';"

The string "paypal is the faster, safer way to send money" is written in a clockwise spiral pattern inside a square starting from the upper left corner: (you may want to display this pattern in a fixed font for better legibility). P A Y P A L F E R W A I A M O N Y S S D Y E T T R N E S O H E T S A F E Then read line after line: PAYPALFERWAIAMONYSSDYETTRNESOHETSAFE Write the code that will take a string, calculate the minimum square that will contain it and return the converted string: String convert(String text); convert("paypalisthefastersaferwaytosendmoney") should return "paypalferwaiamonyssdyettrnesohetsafe"

What is the output for grep 'c[oa]t' *.cpp | more in Unix ? Write a function to convert the string 'abcdabcdac' into 'a3b2c3d2'. Each charater is followed by the number of times in occurs in the original string. What is the order of this function? How would you improve it? Given table A with id, name and age write a query to display distinct pairs or people with same name. Why are indexes used? There was a question based on Diamond inheritance hierarchy in C++. What are static functions in C++? What is the difference between simple function, virtual function and a pure virtual function? What are templates in C++?