perl - Perl 高级排序如何通过使用排序函数中的 $a 和 $b 值对值进行排序

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@array=sort{$a <=> $b} @input;
@input = qw \  3 4 5 1 6 3 9 \;

这是 Perl 如何在内部对值进行排序的。

那么perl高级排序中值的排序方式以及使用哪种排序方法对值进行排序以及如何排序？

Answer 1

perldoc sort :

Perl 5.6 and earlier used a quicksort algorithm to implement sort. That algorithm was not stable and could go quadratic. (A stable sort preserves the input order of elements that compare equal. Although quicksort's run time is O(NlogN) when averaged over all arrays of length N, the time can be O(N**2), quadratic behavior, for some inputs.) In 5.7, the quicksort implementation was replaced with a stable mergesort algorithm whose worst-case behavior is O(NlogN).