A MERGEABLE DOUBLE-ENDED PRIORITY QUEUE

An implementation of a double-ended priority queue is discussed. This data structure referred to as min-max-pair heap can be built in linear time; the operations Delete-min, Delete-max and Insert take O(log n) time, while Find-min and Find-max run in O(1) time. In contrast to the min-max heaps, it is shown that two min-max-pair heaps can be merged in sublinear time. More precisely, two min-max-pair heaps of sizes n and k can be merged in time O(log (n/k) * log k).