RosettaCodeData/Task/Equilibrium-index/Prolog/equilibrium-index-1.pro
2015-02-20 00:35:01 -05:00

6 lines
161 B
Prolog

equilibrium_index(List, Index) :-
append(Front, [_|Back], List),
sumlist(Front, Sum),
sumlist(Back, Sum),
length(Front, Len),
Index is Len.