Smallest Common Region

You are given some lists of regions where the first region of each list includes all other regions in that list. Naturally, if a region X contains another region Y then X is bigger than Y. Also by definition a region X contains itself.

String to Integer (atoi)

Here we are going to write our own atoi() implementation in Java. Remember in Java you convert a string to an integer using the parseInt method of the Java Integer class. The parseInt method converts the String to an int, and throws a NumberFormatException if the string can’t be converted to an int type.

House Robber

You are a professional robber planning to rob houses along a street. Each house has a certain amount of money stashed, the only constraint stopping you from robbing each of them is that adjacent houses have security system connected and it will automatically contact the police if two adjacent houses were broken into on the same night.