### Load packages
library("imager")
library("data.table")
library("dtplyr")
library("dplyr")
library("readr")
library("ggplot2")
library("plotly")
library("mxnet")

#### Alternate cases of dogs and cats
cat_files<- list.files(path = "../input/train", pattern = "cat.+")
dog_files<- list.files(path = "../input/train", pattern = "dog.+")

### randomize image order
set.seed(123)
cat_files<- sample(cat_files)
dog_files<- sample(dog_files)

### list test files
test_files<- list.files(path = "../input/test", pattern = ".+\\.jpg")
test_num<- as.numeric(gsub(pattern="(\\d+)(.+)", replacement = "\\1", x = test_files))
test_position<- order(test_num)
test_files<- test_files[test_position]

head(cat_files)
head(dog_files)
head(test_files)