In the Girls and cannibals problem, three girls and three cannibals must cross a river using a boat which can carry at most two people, under the constraint that, for both banks, if there are girls present on the bank, they cannot be outnumbered by cannibals (if they were, the cannibals would eat the girls). The boat cannot cross the river by itself with no people on board. And, in some variations
**Algorithms --> Depth-first search (DFS)