You are climbing a stair case. It takes n steps to reach to the top.

Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb to the top?

Given a m x n matrix, if an element is 0, set its entire row and column to 0. Do it in place.

Given n non-negative integers a1, a2, …, an, where each represents a point at coordinate (i, ai). n vertical lines are drawn such that the two endpoints of line i is at (i, ai) and (i, 0). Find two lines, which together with x-axis forms a container, such that the container contains the most water.

Find the contiguous subarray within an array (containing at least one number) which has the largest sum.

Given a linked list, determine if it has a cycle in it.