Cody

# Problem 659. How long is the longest prime diagonal?

Solution 1250973

Submitted on 14 Aug 2017 by Michelangelo Ricciulli
This solution is locked. To view this solution, you need to provide a solution of the same size or smaller.

### Test Suite

Test Status Code Input and Output
1   Pass
n = 4; d = 2; %p = isprime(spiral(n));imagesc(p) assert(isequal(prime_spiral(n),d))

n = 4 lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 1 lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 1

2   Pass
n = 7; d = 4; assert(isequal(prime_spiral(n),d))

n = 7 lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 1 lgtn = 3 lgtn = 0×1 empty double column vector lgtn = 4 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 1

3   Pass
n = 13; d = 5; assert(isequal(prime_spiral(n),d))

n = 13 lgtn = [] lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 3 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 1 lgtn = 3 lgtn = 0×1 empty double column vector lgtn = 5 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 4 lgtn = 0×1 empty double column vector lgtn = 3 lgtn = 0×1 empty double column vector lgtn = 0×1 empty double column vector lgtn = 0×1 empty double column vector lgtn = 1

4   Pass
n = 52; d = 6; assert(isequal(prime_spiral(n),d))

n = 52 lgtn = [] lgtn = 0×1 empty double column vector lgtn = 0×1 empty double column vector lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 3 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 5 lgtn = 0×1 empty double column vector lgtn = 0×1 empty double column vector lgtn = 0×1 empty double column vector lgtn = 3 lgtn = 0×1 empty double column vector lgtn = 4 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 4 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 4 lgtn = 0×1 empty double column vector lgtn = 3 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 1 lgtn = 3 lgtn = 0×1 empty double column vector lgtn = 5 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 6 lgtn = 0×1 empty double column vector lgtn = 5 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 4 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 4 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 3 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 6 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 0×1 empty double column vector lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 1

5   Pass
n = 81; d = 9; assert(isequal(prime_spiral(n),d))

n = 81 lgtn = [] lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 0×1 empty double column vector lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 6 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 3 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 3 lgtn = 0×1 empty double column vector lgtn = 3 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 5 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 3 lgtn = 0×1 empty double column vector lgtn = 4 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 4 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 4 lgtn = 0×1 empty double column vector lgtn = 3 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 1 lgtn = 3 lgtn = 0×1 empty double column vector lgtn = 5 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 6 lgtn = 0×1 empty double column vector lgtn = 5 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 4 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 4 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 3 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 4 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 6 lgtn = 0×1 empty double column vector lgtn = 3 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 3 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 2 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 3 lgtn = 0×1 empty double column vector lgtn = 5 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 0×1 empty double column vector lgtn = 0×1 empty double column vector lgtn = 1 lgtn = 0×1 empty double column vector lgtn = 1