library(permute)
set.seed(42)
exampledf<- data.frame(allPerms(c(1,2,3,4)))
exampledf<-head(exampledf)

apply(exampledf,2,function(x){
    ll<-x[1]==1
    which(ll==T)
    })

X1 X2 X3 X4
1  1  2  4  3
2  1  3  2  4
3  1  3  4  2
4  1  4  2  3
5  1  4  3  2
6  2  1  3  4

X1
X1
X1
X1
X1
X2

# construct sample data.frame
set.seed(1234)
df <- data.frame(matrix(
                 c(sample(1:4, 4), sample(1:4, 4),
                   sample(1:4, 4), sample(1:4, 4)),
                 ncol=4, byrow=T))
# name data.frame
names(df) <- c(paste0("x", 1:4))

# get names of variables
names(df)[apply(df, 1, function(i) which(i == 1))]

names(df)[which(df == 1, arr.ind=T)[, "col"]]

library(permute)
set.seed(42)
exampledf <- data.frame(allPerms(c(1,2,3,4)))
exampledf <- head(exampledf)

matched_cols = c()
for(i in 1:nrow(exampledf)){
    row <- edf[i, ] == 1
    matched_col <- colnames(exampledf)[row == T]
    matched_cols = c(matched_cols, matched_col)
}
matched_cols

library(permute)
set.seed(42)
exampledf<- data.frame(allPerms(c(1,2,3,4)))

for(i in 1:nrow(exampledf)){
    for (j in 1:length(exampledf[i,])){
        if(exampledf[i,j]==1){
           print(names(exampledf)[j])
        }
    }
}