no algorithm of the following form: " m and n m elements are sorted using the Ford–Johnson algorithm first, then the sorted sequences are merged", whose total number of used comparisons is smaller than the number of comparisons used by the Ford–Johnson algorithm to sort n elements ...
SPFA (Shortest Path Faster Algorithm) 适用于单源、可有负权边的有向图;大多数时候当图存在负权边,Dijkstra不能使用,而Bellman-Ford时间复杂度过高,所以最好使用SPFA;其实SPFA是Bellman-Ford的优化版本,时间复杂度为O(kE),K是一个远小于V的数字,表示所有顶点进入FQ队列的平均次数(<=2),但是SPFA及...
Significant improvements to the Ford-Johnson algorithm for sorting - Bui, Thanh - 1985 () Citation Context ... 1959) propose an algorithm called merge insertion which comes very close to the theoretical limit. This algorithm is sketched in Figure 1. There are also algorithms with a better ...