  Re-Pair is a grammar compression scheme with favorably good compression
rates. The computation of Re-Pair comes with the cost of maintaining large
frequency tables, which makes it hard to compute Re-Pair on large scale data
sets. As a solution for this problem we present, given a text of length $n$
whose characters are drawn from an integer alphabet, an $O(n^2) \cap O(n^2 \lg
\log_\tau n \lg \lg \lg n / \log_\tau n)$ time algorithm computing Re-Pair in
$n \lg \max(n,\tau)$ bits of space including the text space, where $\tau$ is
the number of terminals and non-terminals. The algorithm works in the restore
model, supporting the recovery of the original input in the time for the
Re-Pair computation with $O(\lg n)$ additional bits of working space. We give
variants of our solution working in parallel or in the external memory model.
