F floyd_warshall(n, edge)
   V rn = 0 .< n
   V dist = rn.map(i -> [1'000'000] * @n)
   V nxt  = rn.map(i -> [0]         * @n)
   L(i) rn
      dist[i][i] = 0
   L(u, v, w) edge
      dist[u - 1][v - 1] = w
      nxt[u - 1][v - 1] = v - 1
   L(k, i, j) cart_product(rn, rn, rn)
      V sum_ik_kj = dist[i][k] + dist[k][j]
      I dist[i][j] > sum_ik_kj
         dist[i][j] = sum_ik_kj
         nxt[i][j] = nxt[i][k]
   print(‘pair      dist     path’)
   L(i, j) cart_product(rn, rn)
      I i != j
         V path = [i]
         L path.last != j
            path.append(nxt[path.last][j])
         print(‘#. -> #.  #4       #.’.format(i + 1, j + 1, dist[i][j], path.map(p -> String(p + 1)).join(‘ -> ’)))

floyd_warshall(4, [(1, 3, -2), (2, 1, 4), (2, 3, 3), (3, 4, 2), (4, 2, -1)])