如何让这个金字塔更加尖锐？

Question

此ruby代码生成金字塔：

w = 20
1.upto(w) { |i| puts ">"+" "*(w-i)+"."*i*2+" "*(w-i)+"<" }

像这样：

>                   ..                   <
>                  ....                  <
>                 ......                 <
>                ........                <
>               ..........               <
>              ............              <
>             ..............             <
>            ................            <
>           ..................           <
>          ....................          <
>         ......................         <
>        ........................        <
>       ..........................       <
>      ............................      <
>     ..............................     <
>    ................................    <
>   ..................................   <
>  ....................................  <
> ...................................... <
>........................................<

我想让金字塔顶部有一个点而不是两个（目前因为"."*i*2使其对称）。

我怎样才能做到这一点？

Answer 1

w=20; 1.upto(w) { |i| puts ">"+" "*(w-i)+"."*(i*2-1)+" "*(w-i)+"<" }

Answer 2

您使用的是固定宽度的字体，因此无法将句点置于当前金字塔之上。你需要使用奇数个点而不是偶数：

w = 20
1.upto(w) do |i|
  spaces = " " * (w-i)
  dots   = "." * (i*2 - 1) # Use one fewer dot per line, starting with one dot
  puts ">" + spaces + dots + spaces + "<"
end

这会产生：

>                   .                   <
>                  ...                  <
>                 .....                 <
>                .......                <
>               .........               <
>              ...........              <
>             .............             <
>            ...............            <
>           .................           <
>          ...................          <
>         .....................         <
>        .......................        <
>       .........................       <
>      ...........................      <
>     .............................     <
>    ...............................    <
>   .................................   <
>  ...................................  <
> ..................................... <
>.......................................<

Answer 3

使用times会使其更清晰。此外，还有center简化了事情：

20.times{|i| puts ">#{("."*(i*2+1)).center(39)}<"}

Answer 4

S, W = ' ', 20; 1.upto(W) {|i| n = W - i; puts ">#{S*n + '.' * (2*i - 1) + S*n}<"}