BSEARCHQQ
Run-Time Function: Performs a binary search
of a sorted one-dimensional array for a specified element. The array elements
cannot be derived types or structures.
Module: USE DFLIB
Syntax
- result = BSEARCHQQ (adrkey,
adrarray, length, size)
- adrkey
(Input) Address of the variable containing the element
to be found (returned by LOC). INTEGER(4) on ia32 processors;
INTEGER(8) on ia64 processors.
- adrarray
(Input) Address of the array (returned by LOC).
INTEGER(4) on ia32 processors; INTEGER(8) on ia64 processors.
- length
(Input) INTEGER(4). Number of elements in the array.
- size
(Input) INTEGER(4). Positive constant less than 32,767 that specifies
the kind of array to be sorted. The following constants, defined
in DFLIB.F90 in the \DF98\INCLUDE subdirectory,
specify type and kind for numeric arrays:
| Constant |
Type of array |
| SRT$INTEGER1 |
INTEGER(1) |
| SRT$INTEGER2 |
INTEGER(2) or equivalent |
| SRT$INTEGER4 |
INTEGER(4) or equivalent |
| SRT$REAL4 |
REAL(4) or equivalent |
| SRT$REAL8 |
REAL(8) or equivalent |
If the value provided in size is not a
symbolic constant and is less than 32,767, the array is assumed to be a
character array with size characters per element.
Results:
INTEGER(4). Array index of the matched entry,
or 0 if the entry is not found.
The array must be sorted in ascending order before
being searched.
Caution:
The location of the array and the
element to be found must both be passed by address using the LOC
function. This defeats Fortran type checking, so you must make certain
that the length and size arguments are correct, and that
size is the same for the element to be found and the array searched.
If you pass invalid arguments, BSEARCHQQ
attempts to search random parts of memory. If the memory it attempts to
search is allocated to the current process, that memory is searched. If
the memory it attempts to search is not allocated to the current process,
the operating system intervenes, the program is halted, and you receive
a General Protection Violation message.
Compatibility
CONSOLE STANDARD GRAPHICS QUICKWIN GRAPHICS WINDOWS DLL
LIB
See Also: SORTQQ, LOC
Example
USE DFLIB
INTEGER(4) array(10), length
INTEGER(4) result, target
length = SIZE(array)
...
result = BSEARCHQQ(LOC(target),LOC(array),length,SRT$INTEGER4)