Databases
StackOverflow2013
Postsdbo
POC++ mpir : How to initialize mpz_t array?
Body
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POC++ mpir : How to initialize mpz_t array?
    text
    copied!<p><strong>Source:</strong></p> <pre><code>//$ DO DECLARATION #define VEC_MAX_SIZE 600000 mpz_t Vec[ VEC_MAX_SIZE ]; //$ DO INITIALIZATION mpz_array_init( Vec[ 0 ], VEC_MAX_SIZE, 2000 ); // Stack overflow error - 3rd param </code></pre> <p><strong>Problem:</strong></p> <p>The problem is that I don't know how to properly initialize an mpz_t array, which in this case is Vec. The error is stack overflow. I think it is caused by the 3rd parameter. Here is the protype/definition of mpz_array_init:</p> <pre><code>#define mpz_array_init __gmpz_array_init __GMP_DECLSPEC void mpz_array_init __GMP_PROTO ((mpz_ptr, mp_size_t, mp_size_t)); </code></pre> <p><strong>Error:</strong></p> <pre><code>Unhandled exception at 0x008e8377 in TestMPIR.exe: 0xC00000FD: Stack overflow. </code></pre> <p><strong>Note:</strong></p> <p>I am using mpir 3.1.1 on Windows 7 64 Bit.</p> <p>This one from mpir's example works fine:</p> <pre><code>mpz_t Vec[ 20000 ]; mpz_array_init( Vec[ 0 ], 20000, 512 ); </code></pre> <p><strong>ANSWER:</strong></p> <p>Thanks to @Zeta for his/her awesome answer. Correct me if I am wrong. I just want to post this here so other newbies can learn from it.</p> <pre><code>#define MAX_VEC_SIZE 600000 </code></pre> <p><strong>malloc method (should be for C style I guess):</strong></p> <pre><code>mpz_t *Vec; if( ( Vec = ( mpz_t *)::malloc( sizeof( mpz_t ) * MAX_VEC_SIZE ) ) == 0 ) { ::perror( "Out of memory" ); return false; } //&gt; Initialize Vec loop ( ... ) ::free( Vec ); </code></pre> <p><strong>C++ style?</strong></p> <pre><code>mpz_t *VecEx = new mpz_t[ MAX_VEC_SIZE ]; //&gt; Initialize VecEx loop ( ... ) delete [ ] VecEx; </code></pre> <p>This answer is based on @Zeta's answer (the accepted answer).</p>
 

Querying!

 
Guidance
An individual column

Larger individual text columns get their own page to allow for proper reading.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload