China DOS Union

Comrade, it seems that among these 72 numbers, 8 numbers are repeated:

4730

5134

4828

4724

4720

4742

4760

4754

Do we only need to consider the other 64 numbers?!

It's not like that. For example: 4078 + 4078 + 4078 + 4052 + 4650 = 20936. If there are 3 4078s in test.txt, the above formula is allowed to appear.

This further increases the difficulty!

If only considering 64 non - repeating numbers, according to the calculation, at least 35 numbers are needed, and at most 37 numbers

This is an inevitable situation in practical applications. That is to say, if the code doesn't calculate the repeated numbers, it's just to practice everyone's hands, not to solve my problem. Please understand.

In fact, excluding the number of combined numbers between 35 and 37, according to the conventional method, the possible number of combinations is still an extremely large number.

It seems to take a lot of time, hehe, not tested

SETLOCAL ENABLEDELAYEDEXPANSION

for /f %%i in (data.txt) do (

set /a a1+=1

set _data!a1!=%%i)



for /l %%a in (1,3,%a1%) do (

set /a b=%%a+1

for /l %%b in (!b!,1,!b!) do (

set /a c=!b!+1

for /l %%c in (!c!,1,!c!) do (

set /a d=!c!+1

for /l %%d in (!d!,1,%a1%) do (

set /a z="1/(171780-!_data%%a!-!_data%%b!-!_data%%c!-!_data%%d!)"||echo !_data%%a!+!_data%%b!+!_data%%c!+!_data%%d!^=171780&&set /a _data%%a=0,_data%%b=0,_data%%c=0,_data%%d=0)

)

)

)



set

pause

[ Last edited by everest79 on 2007-3-2 at 06:33 PM ]

Oh, it turned out to be a four-digit number, I mistook it for a five-digit number

Can't write anymore, too much

Such a difficult question is finally posted. Oh~ I can't figure it out, looking forward to experts

Just a single math problem can kill a lot of brain cells, let alone designing an algorithm. -_-!

Sorted:

3800

3858

4072

4162

4168

4188

4238

4240

4262

4270

4272

4322

4324

4498

4520

4616

4632

4682

4684

4704

4710

4712

4720

4720

4724

4724

4730

4730

4732

4742

4742

4744

4746

4754

4754

4760

4760

4762

4770

4776

4782

4784

4792

4808

4816

4824

4826

4828

4828

4830

4838

4896

4942

4948

5008

5076

5104

5130

5134

5134

5150

5164

5168

5174

5194

5206

5218

5224

5234

5266

5282

5348

Sum of the largest 38 numbers
5348+5282+5266+5234+5224+5218+5206+5194+5174+5168+5164+5150+5134+5134+5130+5104+5076+5008+4948+4942+4896+4838+4830+4828+4828+4826+4824+4816+4808+4792+4784+4782+4776+4770+4762=175264

Sum of the smallest 39 numbers
3800+3858+4072+4162+4168+4188+4238+4240+4262+4270+4272+4322+4324+4498+4520+4616+4632+4682+4684+4704+4710+4712+4720+4720+4724+4724+4730+4730+4732+4742+4742+4744+4746+4754+4754+4760+4760+4762+4770=176548>171780
Then what does this indicate? It can only be 38 digits. (I casually calculated that the sum of the smallest 38 is 171778)


Thus, the number of digits is limited! The number of operations is reduced from 2^72 - 1 to 396561735952215036840 times, which is approximately 344 * 2^60 times... Although it is very large, you should know that 2^72 is about 11.9 times of it!
And the number of operations can be further reduced...

The sum of the smallest 38 numbers has a difference of 2 from the required number (171780 - 171778 = 2)

3800 + 3858 + 4072 + 4162 + 4168 + 4188 + 4238 + 4240 + 4262 + 4270 + 4272 + 4322 + 4324 + 4498 + 4520 + 4616 + 4632 + 4682 + 4684 + 4704 + 4710 + 4712 + 4720 + 4720 + 4724 + 4724 + 4730 + 4730 + 4732 + 4742 + 4742 + 4744 + 4746 + 4754 + 4754 + 4760 + 4760 + 4762

And the 39th number is 4770. The number closest to it is the 38th one (I sorted them in order). And this number 4762 has a difference from 4770 that is greater than 2.

That is to say, if 39 is replaced with 38, the number becomes larger by 6 (171786). And this number is the 2nd smallest number among the 38 numbers. All the subsequent numbers are larger than it!

So the final answer comes out!!!!!

No qualifying combination

re slore
There won't be no qualifying combinations as you said, because I got this result after a selection and then made the question.

Originally posted by ccwan at 2007-3-3 08:49:
re slore
There won't be no combination that meets the requirements as I got this result after a selection, and then made the question.

Is your number 38?

Send me the short message with your number.
I think the analysis is not wrong... It won't be a calculation issue~

Sorry,Irandomlyselectedsomenumbers,gotaresultandsentitout,withoutrecordingwhichnumberstheywere,buttheremustbesuchcombinations.

Ifduetomyoversighttherereallyaren'tany,youcandefineoneyourselfaslongasitworks.