删除出现在一个元素及其本身之前的元素 [英] Delete elements appearing before one element and itself

问题描述

我有一个元素列表(示例中为字母)

I have a list of elements (letter here in the example)

 (l <- list(letters[1:2], letters[2:3]))

# [[1]]    
# [1] "a" "b"    
# [[2]]   
# [1] "b" "c" 

 And another elements 
(r <- letters[2])

# [1] "b"

R函数必须删除"b"和"b"本身之前的evrything.

The R function must delete evrything before "b" and "b" itself.

结果将是这样的:

 # [[1]]    
 # [1] "c"

请问有什么主意吗?

提前谢谢

推荐答案

尝试

out = lapply(l, function(x) x[-c(1,which(x == "b"))])
Filter(length, out)

#[[1]]
#[1] "c"

或按照@akrun的建议

or as @akrun suggested

Filter(length,lapply(l, function(x) x[-seq(match("b",x))]))

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