Mercurial > octave-nkf
view liboctave/UMFPACK/UMFPACK/Source/umf_is_permutation.c @ 5164:57077d0ddc8e
[project @ 2005-02-25 19:55:24 by jwe]
author | jwe |
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date | Fri, 25 Feb 2005 19:55:28 +0000 |
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/* ========================================================================== */ /* === UMF_is_permutation =================================================== */ /* ========================================================================== */ /* -------------------------------------------------------------------------- */ /* UMFPACK Version 4.4, Copyright (c) 2005 by Timothy A. Davis. CISE Dept, */ /* Univ. of Florida. All Rights Reserved. See ../Doc/License for License. */ /* web: http://www.cise.ufl.edu/research/sparse/umfpack */ /* -------------------------------------------------------------------------- */ /* Return TRUE if P is a r-permutation vector, FALSE otherwise */ /* P [0..r-1] must be an r-permutation of 0..n-1 */ #include "umf_internal.h" GLOBAL Int UMF_is_permutation ( const Int P [ ], /* permutation of size r */ Int W [ ], /* workspace of size n */ Int n, Int r ) { Int i, k ; if (!P) { /* if P is (Int *) NULL, this is the identity permutation */ return (TRUE) ; } ASSERT (W != (Int *) NULL) ; for (i = 0 ; i < n ; i++) { W [i] = FALSE ; } for (k = 0 ; k < r ; k++) { i = P [k] ; DEBUG5 (("k "ID" i "ID"\n", k, i)) ; if (i < 0 || i >= n) { DEBUG0 (("i out of range "ID" "ID"\n", i, n)) ; return (FALSE) ; } if (W [i]) { DEBUG0 (("i duplicate "ID"\n", i)) ; return (FALSE) ; } W [i] = TRUE ; } return (TRUE) ; }