//------------------------------------------------------------------------------
// SPEX_Utilities/spex_matrix_mul: multiplies a MPZ matrix by a scalar
//------------------------------------------------------------------------------

// SPEX_Utilities: (c) 2019-2024, Christopher Lourenco, Jinhao Chen,
// Lorena Mejia Domenzain, Erick Moreno-Centeno, and Timothy A. Davis.
// All Rights Reserved.
// SPDX-License-Identifier: GPL-2.0-or-later or LGPL-3.0-or-later

//------------------------------------------------------------------------------

/* Purpose: This function multiplies the matrix x (CSC, triplet, or dense) by a
 * scalar.  This function requires x to have type mpz_t.
 *
 * On output the values of x are modified.
 */

#include "spex_util_internal.h"

SPEX_info spex_matrix_mul   // multiplies x by a scalar
(
    SPEX_matrix x,          // matrix to be multiplied
    const mpz_t scalar      // scalar to multiply by
)
{

    //--------------------------------------------------------------------------
    // check inputs
    //--------------------------------------------------------------------------

    if (!spex_initialized ( )) return (SPEX_PANIC);
    SPEX_info info ;
    SPEX_REQUIRE_TYPE (x, SPEX_MPZ);


    //--------------------------------------------------------------------------
    // x = x * scalar
    //--------------------------------------------------------------------------

    int64_t nz;
    info = SPEX_matrix_nnz (&nz, x, NULL);
    if (info != SPEX_OK) {return info;}

    for (int64_t i = 0; i < nz; i++)
    {
        // x[i] = x[i]*scalar
        SPEX_MPZ_MUL( x->x.mpz[i], x->x.mpz[i], scalar);
    }

    return (SPEX_OK);
}