forgetful hill climbing

The simplest form of hill climbing search is 'forgetful', that is at each step one moves to an adjoining or close point with a better (or best) fitness function. The is has the danger of getting stuck at a local maxima or reach an impasse if some states are not allowed, for example those that are not feasible when there are constraints. For this reason, some variants of hill climbing are not forgetful and instead keep track of past states (memory) and use backtracking to revisit them in case of impasse, or to explore alternatives such as next best solution.