r - 编写一个名为 steps() 的函数，它为任何 n 构建一个方形楼梯

Question

我是 R 新手，并试图弄清楚如何解决这个问题。编写一个名为 steps() 的函数，它为任何 n 构建一个方形楼梯。

这是我最初拥有的

steps<- function(n)

{
  mx <- matrix(,nrow=n,ncol = n)

  for( n in 1:n)
  {
    mx[n,n] = "#"


  }

  print(mx)
}

标签： r

Answer 1

steps <- function(n) {
  m <- matrix('', n, n)
  m[!upper.tri(m)[,n:1]] <- '#'
  m
}
steps(5)


#     [,1] [,2] [,3] [,4] [,5]
# [1,] ""   ""   ""   ""   "#" 
# [2,] ""   ""   ""   "#"  "#" 
# [3,] ""   ""   "#"  "#"  "#" 
# [4,] ""   "#"  "#"  "#"  "#" 
# [5,] "#"  "#"  "#"  "#"  "#" 

如果（像您的图像）您不想看到引号，那么

print(steps(5), quote = FALSE)
#      [,1] [,2] [,3] [,4] [,5]
# [1,]                     #   
# [2,]                #    #   
# [3,]           #    #    #   
# [4,]      #    #    #    #   
# [5,] #    #    #    #    #