Solution Parse input and build the tree by maintaining an index HashMap.

Solution #1 Keep indexes of all numbers in a HashMap. Check if current maximum number is already at desired index i.

Solution Iterate through each house in a sorted order. Check if current house is in range of last transmitter.

Solution #1 Keep prices and corresponding index in a HashMap. Sort the prices array in ascending order so that combination of minimum difference can be found by comparing adjacent prices.

Solution Start iterating numbers from b to a because combination of larger numbers are more likely to be indivisible.

Solution Iterate from 2 to the given number. Consider odd numbers only except 2.

Solution Iterate from 1 to given number. Add each iteration to sum and square of it to another sum.

Solution Iterate from the given number to zero. Check if current iteration is a palindrome by using reverse() of StringBuilder class.

Solution Find all the factors of the given number by iterating from 1 to square root of the number.

Solution #1 Test cases 2,3 timed out for below solution.