Find indicies of unsorted locations in an array

2 次查看（过去 30 天）

显示更早的评论

Erez 2019-4-2

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/453866-find-indicies-of-unsorted-locations-in-an-array

评论： Stephan 2019-4-2

在 MATLAB Online 中打开

I have a long array, e.g.

A=[ 1 2 5 8 7 9 110 100]

I want to get an array B, which contains the left-index of the positions where the array is not sorted (the array is supposed to be sorted from the lowest value on the left, to the highest value on the right), namely

B=[4,7]

How can I do that without using loops?

Another example, just to make the point clear: I assume that the array is more-or-less already sorted, so AA=[-1 1 3 2 0] does not occur, but AA=[-1 1 3 2 5] does.

The latter will yield: B=[3].

Also AA=[-1 1 8 2 3] does not occur. I assume that if there are non-sorted positions, then by switching the locations of only nearest neighbours (i, i+1) I can make the array sorted again.

Thanks!