Running time of common time complexities

big_o.r

big_O.plot <- function(count,log="") {
  n <- seq(count)

  plot(n, n*n, log=log, type='l', col='red',
    ylab="Running time", xlab='n (# of elements)')
  lines(n, n*log(n), col='green')
  lines(n, n, col='blue')
  lines(n, log(n), col='black')

  title('Running time of common time complexities')
  legend('topleft', lty=1, cex=0.8, inset=.025,
    title='Big O notation',
    c(
      expression(paste("O(", n^2, ")")),
      expression(paste("O(", n*log(n), ")")),
      expression(paste("O(", n, ")")),
      expression(paste("O(", log(n), ")"))
    ),
    col=c('red','green','blue','black')
  )
}

png('time_complexity_10.png')
big_O.plot(10)

png('time_complexity_1000.png')
big_O.plot(1000)

png('time_complexity_10000.png')
big_O.plot(10000)