R code to insert rows based on a column's value and increment it by 1

Question

I have two columns in my data as shown below. I want to insert rows based on the value in Total column. Eg. For record1, the total value is 9. So, there should be 9 records for

Answer 1

library(data.table)
setDT(df)[,.(Total=1:Total), code]

Or base R:

with(df, data.frame(code=rep(code, Total), Total=sequence(Total)))