问如何从更新的四个动态和不规则向量生成data.frame？

EN

cbind.fill <- function(...){
nm <- list(...) 
nm <- lapply(nm, as.matrix)
n <- max(sapply(nm, nrow)) 
do.call(cbind, lapply(nm, function (x) 
    rbind(x, matrix(, n-nrow(x), ncol(x))))) 
}

X<-matrix(t(X),ncol=1)

d1 <- data.frame(lapply(lst, `length<-`, max(lengths(lst))))
unlist(apply(d1, 1, FUN = function(x) sort(x)))

lst <- list(A = c(1, 5, 7, 5), B = c(3, 4, 6, 2, 5), C  = c(5, 3, 2), 
             D = c(8, 1, 3, 5, 6))

lst <- lapply(mget(LETTERS[1:4]),`[`,,1L);
lst;
## $A
## [1] 37 56
##
## $B
## [1] 94 65 61  5 19
##
## $C
## [1] 99 37 76 90
##
## $D
## [1]  1 37
##
c(sapply(seq_len(max(lengths(lst))),function(i) sapply(lst,`[`,i)));
##  [1] 37 94 99  1 56 65 37 37 NA 61 76 NA NA  5 90 NA NA 19 NA NA

set.seed(1L);
for (n in LETTERS[1:4]) assign(n,matrix(sample(0:99,sample(1:5,1L)*2L),ncol=2L));