The idea is that as time goes by, computers become twice as fast (Moore's law), but problems also become twice as big. With a quadratic algorithm, you will need

The idea is that as time goes by, computers become twice as fast (Moore's law), but problems also become twice as big. With a quadratic algorithm, you will need twice as much time to solve the problems of the bigger size, even on the faster computer. See page 22 of http://www.cs.princeton.edu/courses/archive/spr15/cos126/lectures/41analysis.pdf http://www.cs.princeton.edu/courses/archive/spr15/cos126/lec...