#! /bin/sh
awk -F! '{ count[NF] += 1; if (NF > mx) mx = NF; sum += NF; }
END { printf ("Path length statistics\nAverage length: %f\nHistogram:\n",
		sum / NR);
      for (i = 1; i <= mx; i++) printf ("%d %d\n",i,count[i]); }'
