CodePudding user response:

So-called stability, is the number two of the same size, sorting before and after sorting order relation is changeless, is stable, if order relations, is not stable,
Such as the number of three relations of a1=a2 & lt; B, according to the smallest
B, a1, a2//suppose sorting before the order is
A1, a2, b,//if the order is sorted so stable (order unchanged before and after sorting a1, a2)
A2 and a1, b,//if the order is sorted so unstable (order change before and after sorting a1, a2, a2 to a1 top)