Problem 60. The Goldbach Conjecture
Solution Stats
Problem Comments

16 Comments
for n =10,p1=[3 5 7],p2=[7 5 3],is the correct answer. but the judgement is not allowed.
Nice one.
Thank you very much! Its a really nice one!
Well made. I am still trimming down my code furiously. My favorite problem so far.
Currently the best one for me!
nice problem . I like problem related to prime numbers
Very nice problem!
this was a fun one
something I am doing worng.
please help.
p1=[]
p2=[]
for i = 1:5000
x1 = ceil(286*rand(1));
x2 = ceil(286*rand(1));
s = x1+x2;
a =isprime(x1);
b=isprime(x2);
if a==1 && b==1 && s ==n
p1=x1
p2=x2
end
end
[p1 p2]
cool
有中国的小伙伴吗？
Really interesting the Goldbach conjecture!
有中国的小伙伴呀
At first,I thought I should find all the possible answers.But I misunderstood the text............
nice question
perfect nice
Solution Comments

1 Comment
Happier now. Loop though nList handled in test suite. No loop in my function and returns the 2 primes closest together

1 Comment
given that the looping through nList is handled in the test suite, I don't need to.

1 Comment
returning single value of prime pair instead of vector will help

1 Comment
with functions like nchoosek and primes, it is quite easy

1 Comment
tai tama nan le.:)

2 Comments
Forgetting 1 isn't prime doesn't help
See https://en.wikipedia.org/wiki/Prime_number#Primality_of_one

2 Comments
my solution is correct,, what is the problem
Problem is with the test suite it expects just 2 numbers and you generated vector of all possible solutions, if you return after finding the first pair it will work.

1 Comment
Lists all of them.

1 Comment
High score but simple and two lines.

2 Comments
Can't use combnk()? Getting an error for using?
Oh, I can use nchoosek() instead...

1 Comment
Bizarrely I couldn't submit this solution when b, b1 and b2 were labelled p, p1 and p2 due to 'inappopriate content'. I'd be interested to know what looked so inappropriate...

1 Comment
Why is this not working?

1 Comment
how nice

1 Comment
n  (1:n) can be written as (n1):1:0

1 Comment
This one passed tests, but solves another problem: p1 is odd and p2 is prime. It fails to find 2+2=4 and finds incorrectly 9+89=98.

1 Comment
This is the best I can do...

1 Comment
Although the naming of primes is a poor choice,
primes = primes(nums);
can replace:
nums=2:n;
primes=nums(isprime(nums));

1 Comment
Although it passes the test suite, this solution is incorrect for n = 4, 6. The main reason for this error is that the nested loop for j is incorrect. It should be for j=i:c

1 Comment
It would be interesting that the test suite does the assertion on all entries of p1 & p2 in case they return all possible solutions.
assert(all(isprime(p1) & isprime(p2) & (p1+p2==n))

1 Comment
This is a very interesting approach to the problem  learned something new today :D.

2 Comments
I dont understand what the problem with solution is ?
Your for loop bounds exceed the number of prime factors of n. Also, it looks like you are solving for the stated case n=286 and the test cases are using additional inputs.

1 Comment
To compute all possible.. replace b=find(isprime(p2),1,'first'); with b=isprime(p2);
enjoy

2 Comments
smart and short... i needed a "few" lines more :)
smart!

2 Comments
Shouldn't pass, but does. No check of both numbers being primenumbers
I see your point. You were lucky with the original test suite, but I've added a few more test points. Thanks.

1 Comment
Nice! I didn't know they have a function for C_n^k before.

1 Comment
Sometimes vectorized code is not the shortest.
Problem Recent Solvers4826
Suggested Problems

1960 Solvers

2442 Solvers

Project Euler: Problem 4, Palindromic numbers
760 Solvers

696 Solvers

ベクトル [1 2 3 4 5 6 7 8 9 10] の作成
451 Solvers
More from this Author96
Problem Tags
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!