我没有仔细考虑这个问题，但这是我在正则表达式中使用引用的快速解决方案:

I did not think very carefully on this, but this is my quick solution using references in regular expressions:

gsub('([[:alpha:]])\\1+', '\\1', 'Buenaaaaaaaaa Suerrrrte')
# [1] "Buena Suerte"

()先捕获一个字母，\\1指那个字母，+表示匹配一次或多次；将所有这些部分放在一起，我们可以将一个字母匹配两次或更多次.

() captures a letter first, \\1 refers to that letter, + means to match it once or more; put all these pieces together, we can match a letter two or more times.

要包含字母数字以外的其他字符，请将 [[:alpha:]] 替换为与您希望包含的任何内容匹配的正则表达式.

To include other characters besides alphanumerics, replace [[:alpha:]] with a regex matching whatever you wish to include.