China DOS Union

About the algorithm of +-:

I did this before, but, let's continue to think with cups. Even if the two liquids are incompatible, but to pour the liquids from the two cups into one cup, then you can only pour at most half a cup (based on the upper limit for safety consideration, don't say the case where one cup has only the bottom and the other is almost full), otherwise an error will occur due to overflow!!

Originally posted by pengfei at 2007-1-25 23:03:
The use of call %%var1%% by user lxmxn actually does not expand, which is another usage of variable delay like!var!. Therefore, variable exchange cannot be achieved.

　　What I want to express is exactly this kind of invalid example.

Uh, let me say something off-topic. This thing is strongly recommended to be added to the wiki!

Brother est is right, the idea of putting it on Wiki is good. Brother lxmxn pointed out the variable delay. In variable replacement in the script, prevent using delay (such as call delay and!var! delay).

Hehe, learned a little more again

Hehe, it cleverly uses the principle of preprocessing in batch processing. This is also one of the differences between interpreters and compilers. C and C++ have to use temporary variables to complete this exchange.