public int decreaseKey ( E o ) { HeapEntry < E > entry = getEntry ( o ) ; if ( o != entry . object ) { if ( cmp . compare ( o , entry . object ) < 0 ) { entry . object = o ; } } return heapifyUp ( entry ) ; }
Changes the position of an element o in the heap based on a change in the ordering of o . If o s key has actually increased it will do nothing particularly not an increase key .