question (ticket purchase question):
Before the start of a fierce football match, the ticket sales were in a tense way.
Known:
1. Each ticket is 50 yuan.
2. There are now 2n individuals queuing to buy tickets,
There are n individuals hand-held 50 yuan banknotes, the other n individuals holding 100 yuan banknotes,
Suppose there is no change at the ticket office when the ticket is started.
Q: How many kinds of queues does this 2n person have, not to make the ticket office appear to be unable to open the situation of money?
Summary:
Through the analysis of the ticket change problem, migration to the parentheses matching problem, get recursion. Through the knowledge of series power series in mathematical analysis, the recursive pass term is deduced to solve some derivative problems.
Here's how to play the symbol ...
The chain of the stranger.
Http://yunpan.cn/cQNjfVYTQ4PcW Access Password 7549
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Professional Introductory Course paper ...
Wrote for a lot of days, feeling seriously by "Big Ze township" pit 、、、
Completely understand his score basis, hhhhh.
Rotten in my hard drive also wasted,
Send it out (well, no one to see it)
[BOP] [Beauty of programming] [MSRA] From the question of "buying tickets"