$ g++ a25.cpp graph.cpp linear.cpp lt.cpp; a.exe
srand=1143752384
mode=0 ltexcess=20.8754 liexcess=1.61167
mode=1 ltexcess=21 liexcess=2.32997
mode=2 ltexcess=21 liexcess=3.81462
mode=3 ltexcess=21 liexcess=1.21124