1, file descriptor -e Determine whether the object exists
-d Determine whether the object exists and is a directory
-f Determine whether the object exists, and it is a regular file
-L Determine
Tag: judgment
Regular expression – how to determine which alternative items in the Perl regular expression mode?
I have a list of regular expressions (about 10-15) and I need to match some text. Matching them one by one in a loop is too slow. However, I did not write my own state machine To match all regular
[PAT Level] 1043 IS IT A Binary Search Tree (25 points) (Judge whether or not the BST is traversed and outputs traversal traversal)
Title:
Enter a positive integer N (<=1000), and then enter the serial number of N points. If the sequence just entered is a binary search tree or its mirror image (the center is flipped 180°)
Judging whether the binary tree is mirror
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[Data Structure] Judging the legitimacy of the outlet order
A brief description of the problem
Given a stacking order, and then specify a stacking order, the legality of the stacking order is judged by the program.
The idea is as follows:
Delphi judges whether a class implements an interface
TObject.GetInterface can obtain an instance of an object to implement an interface. The prerequisite is that the object must be instantiated before running GetInterface
The following method c
Testflight – I can judge whether my app is running under Apple Test Flight Beta
In the previous test flight system, we promoted the AdHoc build, and we used compiler constants to identify the on/off functions of our beta testers. Now there is Apple’s Beta test Flight system, w
Activiti learning is judged according to the conditions
In process design, we often encounter the problem of judging the process direction based on conditions. The corresponding implementation method is also given in Activiti: gateway.
Gateway (Gatewa