/* zzektrls.f -- translated by f2c (version 19980913).
   You must link the resulting object file with the libraries:
	-lf2c -lm   (in that order)
*/

#include "f2c.h"

/* $Procedure      ZZEKTRLS ( EK tree, linear search ) */
integer zzektrls_(integer *handle, integer *tree, integer *ival)
{
    /* System generated locals */
    integer ret_val, i__1;

    /* Local variables */
    extern /* Subroutine */ int zzektrdp_(integer *, integer *, integer *, 
	    integer *);
    integer i__, n;
    extern integer zzektrsz_(integer *, integer *);
    integer value;

/* $ Abstract */

/*     Search an EK tree linearly to find a specified data value.  The */
/*     function returns the index at which the value is found. */

/* $ Disclaimer */

/*     THIS SOFTWARE AND ANY RELATED MATERIALS WERE CREATED BY THE */
/*     CALIFORNIA INSTITUTE OF TECHNOLOGY (CALTECH) UNDER A U.S. */
/*     GOVERNMENT CONTRACT WITH THE NATIONAL AERONAUTICS AND SPACE */
/*     ADMINISTRATION (NASA). THE SOFTWARE IS TECHNOLOGY AND SOFTWARE */
/*     PUBLICLY AVAILABLE UNDER U.S. EXPORT LAWS AND IS PROVIDED "AS-IS" */
/*     TO THE RECIPIENT WITHOUT WARRANTY OF ANY KIND, INCLUDING ANY */
/*     WARRANTIES OF PERFORMANCE OR MERCHANTABILITY OR FITNESS FOR A */
/*     PARTICULAR USE OR PURPOSE (AS SET FORTH IN UNITED STATES UCC */
/*     SECTIONS 2312-2313) OR FOR ANY PURPOSE WHATSOEVER, FOR THE */
/*     SOFTWARE AND RELATED MATERIALS, HOWEVER USED. */

/*     IN NO EVENT SHALL CALTECH, ITS JET PROPULSION LABORATORY, OR NASA */
/*     BE LIABLE FOR ANY DAMAGES AND/OR COSTS, INCLUDING, BUT NOT */
/*     LIMITED TO, INCIDENTAL OR CONSEQUENTIAL DAMAGES OF ANY KIND, */
/*     INCLUDING ECONOMIC DAMAGE OR INJURY TO PROPERTY AND LOST PROFITS, */
/*     REGARDLESS OF WHETHER CALTECH, JPL, OR NASA BE ADVISED, HAVE */
/*     REASON TO KNOW, OR, IN FACT, SHALL KNOW OF THE POSSIBILITY. */

/*     RECIPIENT BEARS ALL RISK RELATING TO QUALITY AND PERFORMANCE OF */
/*     THE SOFTWARE AND ANY RELATED MATERIALS, AND AGREES TO INDEMNIFY */
/*     CALTECH AND NASA FOR ALL THIRD-PARTY CLAIMS RESULTING FROM THE */
/*     ACTIONS OF RECIPIENT IN THE USE OF THE SOFTWARE. */

/* $ Required_Reading */

/*     EK */

/* $ Keywords */

/*     EK */
/*     PRIVATE */

/* $ Declarations */
/* $ Disclaimer */

/*     THIS SOFTWARE AND ANY RELATED MATERIALS WERE CREATED BY THE */
/*     CALIFORNIA INSTITUTE OF TECHNOLOGY (CALTECH) UNDER A U.S. */
/*     GOVERNMENT CONTRACT WITH THE NATIONAL AERONAUTICS AND SPACE */
/*     ADMINISTRATION (NASA). THE SOFTWARE IS TECHNOLOGY AND SOFTWARE */
/*     PUBLICLY AVAILABLE UNDER U.S. EXPORT LAWS AND IS PROVIDED "AS-IS" */
/*     TO THE RECIPIENT WITHOUT WARRANTY OF ANY KIND, INCLUDING ANY */
/*     WARRANTIES OF PERFORMANCE OR MERCHANTABILITY OR FITNESS FOR A */
/*     PARTICULAR USE OR PURPOSE (AS SET FORTH IN UNITED STATES UCC */
/*     SECTIONS 2312-2313) OR FOR ANY PURPOSE WHATSOEVER, FOR THE */
/*     SOFTWARE AND RELATED MATERIALS, HOWEVER USED. */

/*     IN NO EVENT SHALL CALTECH, ITS JET PROPULSION LABORATORY, OR NASA */
/*     BE LIABLE FOR ANY DAMAGES AND/OR COSTS, INCLUDING, BUT NOT */
/*     LIMITED TO, INCIDENTAL OR CONSEQUENTIAL DAMAGES OF ANY KIND, */
/*     INCLUDING ECONOMIC DAMAGE OR INJURY TO PROPERTY AND LOST PROFITS, */
/*     REGARDLESS OF WHETHER CALTECH, JPL, OR NASA BE ADVISED, HAVE */
/*     REASON TO KNOW, OR, IN FACT, SHALL KNOW OF THE POSSIBILITY. */

/*     RECIPIENT BEARS ALL RISK RELATING TO QUALITY AND PERFORMANCE OF */
/*     THE SOFTWARE AND ANY RELATED MATERIALS, AND AGREES TO INDEMNIFY */
/*     CALTECH AND NASA FOR ALL THIRD-PARTY CLAIMS RESULTING FROM THE */
/*     ACTIONS OF RECIPIENT IN THE USE OF THE SOFTWARE. */


/*     Include Section:  EK Tree Parameters */

/*        ektree.inc  Version 3    22-OCT-1995 (NJB) */


/*     The parameters in this file define the tree structure */
/*     used by the EK system.  This structure is a variant of the */
/*     B*-tree structure described in Knuth's book, that is */

/*         Knuth, Donald E.  "The Art of Computer Programming, */
/*         Volume 3/Sorting and Searching" 1973, pp 471-479. */

/*     The trees used in the EK system differ from generic B*-trees */
/*     primarily in the way keys are treated.  Rather than storing */
/*     unique primary key values in each node, EK trees store integer */
/*     counts that represent the ordinal position of each data value, */
/*     counting from the lowest indexed element in the subtree whose */
/*     root is the node in question.  Thus the keys are unique within */
/*     a node but not across multiple nodes:  in fact the Nth key in */
/*     every leaf node is N.  The absolute ordinal position of a data */
/*     item is defined recursively as the sum of the key of the data item */
/*     and the absolute ordinal position of the data item in the parent */
/*     node that immediately precedes all elements of the node in */
/*     question.  This data structure allows EK trees to support lookup */
/*     of data items based on their ordinal position in a data set.  The */
/*     two prime applications of this capability in the EK system are: */

/*        1) Using trees to index the records in a table, allowing */
/*           the Nth record to be located efficiently. */

/*        2) Using trees to implement order vectors that can be */
/*           maintained when insertions and deletions are done. */



/*                           Root node */

/*        +--------------------------------------------+ */
/*        |              Tree version code             | */
/*        +--------------------------------------------+ */
/*        |           Number of nodes in tree          | */
/*        +--------------------------------------------+ */
/*        |            Number of keys in tree          | */
/*        +--------------------------------------------+ */
/*        |                Depth of tree               | */
/*        +--------------------------------------------+ */
/*        |            Number of keys in root          | */
/*        +--------------------------------------------+ */
/*        |              Space for n keys,             | */
/*        |                                            | */
/*        |        n = 2 * INT( ( 2*m - 2 )/3 )        | */
/*        |                                            | */
/*        |  where m is the max number of children per | */
/*        |          node in the child nodes           | */
/*        +--------------------------------------------+ */
/*        |        Space for n+1 child pointers,       | */
/*        |         where n is as defined above.       | */
/*        +--------------------------------------------+ */
/*        |          Space for n data pointers,        | */
/*        |         where n is as defined above.       | */
/*        +--------------------------------------------+ */


/*                           Child node */

/*        +--------------------------------------------+ */
/*        |        Number of keys present in node      | */
/*        +--------------------------------------------+ */
/*        |              Space for m-1 keys            | */
/*        +--------------------------------------------+ */
/*        |         Space for m child pointers         | */
/*        +--------------------------------------------+ */
/*        |         Space for m-1 data pointers        | */
/*        +--------------------------------------------+ */




/*     The following parameters give the maximum number of children */
/*     allowed in the root and child nodes.  During insertions, the */
/*     number of children may overflow by 1. */


/*     Maximum number of children allowed in a child node: */


/*     Maximum number of keys allowed in a child node: */


/*     Minimum number of children allowed in a child node: */


/*     Minimum number of keys allowed in a child node: */


/*     Maximum number of children allowed in the root node: */


/*     Maximum number of keys allowed in the root node: */


/*     Minimum number of children allowed in the root node: */



/*     The following parameters indicate positions of elements in the */
/*     tree node structures shown above. */


/*     The following parameters are for the root node only: */


/*     Location of version code: */


/*     Version code: */


/*     Location of node count: */


/*     Location of total key count for the tree: */


/*     Location of tree depth: */


/*     Location of count of keys in root node: */


/*     Base address of keys in the root node: */


/*     Base address of child pointers in root node: */


/*     Base address of data pointers in the root node (allow room for */
/*     overflow): */


/*     Size of root node: */


/*     The following parameters are for child nodes only: */


/*     Location of number of keys in node: */


/*     Base address of keys in child nodes: */


/*     Base address of child pointers in child nodes: */


/*     Base address of data pointers in child nodes (allow room */
/*     for overflow): */


/*     Size of child node: */


/*     A number of EK tree routines must declare stacks of fixed */
/*     depth; this depth limit imposes a limit on the maximum depth */
/*     that an EK tree can have.  Because of the large branching */
/*     factor of EK trees, the depth limit is of no practical */
/*     importance:  The number of keys that can be held in an EK */
/*     tree of depth N is */

/*                           N-1 */
/*                     MXKIDC   -  1 */
/*         MXKIDR  *   ------------- */
/*                      MXKIDC  - 1 */


/*     This formula yields a capacity of over 1 billion keys for a */
/*     tree of depth 6. */


/*     End Include Section:  EK Tree Parameters */

/* $ Brief_I/O */

/*     Variable  I/O  Description */
/*     --------  ---  -------------------------------------------------- */
/*     HANDLE     I   File handle. */
/*     TREE       I   Tree root. */
/*     IVAL       I   Value to search for. */

/*     The function returns the lowest index at which the input value */
/*     is found, or zero if the value is not found. */

/* $ Detailed_Input */

/*     HANDLE         is a file handle of an EK open for read or write */
/*                    access. */

/*     TREE           is the root node of the tree to search. */

/*     IVAL           is the value to search for. */

/* $ Detailed_Output */

/*     The function returns the lowest index at which the input value */
/*     is found, or zero if the value is not found. */

/* $ Parameters */

/*     None. */

/* $ Exceptions */

/*     1)  If HANDLE is invalid, the error will be diagnosed by routines */
/*         called by this routine. */

/*     2)  If TREE is invalid, strange errors may result. */

/*     3)  If an I/O error occurs while reading the indicated file, */
/*         the error will be diagnosed by routines called by this */
/*         routine. */

/* $ Files */

/*     See the EK Required Reading for a discussion of the EK file */
/*     format. */

/* $ Particulars */

/*     This searches a tree for a specified value.  It is an approximate */
/*     inverse of ZZEKTRLK.  However, ZZEKTRLK operates in logarithmic */
/*     time (as a function of the tree's size), while this function */
/*     plods along in linear time. */

/* $ Examples */

/*     See ZZEKRP2N. */

/* $ Restrictions */

/*     None. */

/* $ Literature_References */

/*     None. */

/* $ Author_and_Institution */

/*     N.J. Bachman   (JPL) */

/* $ Version */

/* -    Beta Version 1.0.0, 11-OCT-1995 (NJB) */

/* -& */

/*     Non-SPICELIB functions */


/*     Local variables */


/*     Use discovery check-in. */

    ret_val = 0;
    n = zzektrsz_(handle, tree);
    i__1 = n;
    for (i__ = 1; i__ <= i__1; ++i__) {
	zzektrdp_(handle, tree, &i__, &value);
	if (*ival == value) {
	    ret_val = i__;
	    return ret_val;
	}
    }
    return ret_val;
} /* zzektrls_ */

