NAME

int_vector_is_permutation - Test if input contains a permutation

SYNOPSIS

#include "l/l_int_vector.h"

Example compile flags (system dependent):
  -DLINUX_X86_64 -DLINUX_X86_64_OPTERON  -DGNU_COMPILER 
   -I/home/kobus/include
   -L/home/kobus/misc/load/linux_x86_64_opteron -L/usr/lib/x86_64-linux-gnu
  -lKJB                               -lfftw3  -lgsl -lgslcblas -ljpeg  -lSVM -lstdc++                    -lpthread -lSLATEC -lg2c    -lacml -lacml_mv -lblas -lg2c      -lncursesw 


int int_vector_is_permutation
(
	const Int_vector *vp,
	int start_value,
	int *result
);

DESCRIPTION

This is a predicate that tests whether the contents of the Int_vector constitute a permutation (possibly with an offset value). If the input pointer vp equals NULL or *vp contains zero elements, the result is trivially true. Otherwise, suppose vp -> size equals N. Informally, this tests whether the vector is a "shuffling" of the integers

 start_value, start_value+1, . . ., start_value+N-1

without any repetitions or missing numbers. To be more formal, this tests whether the function p is a permutation (a.k.a. a bijection, a.k.a. a one-to-one mapping from D onto D) where p and D are defined like so: | p : D --> D

 D = {0, 1, 2, . . ., N-1}
 p(i) = vp -> elements[i] - start_value

RETURNS This returns ERROR if we cannot allocate the auxiliary array this routine needs, or if output parameter 'result' equals NULL. Otherwise this returns NO_ERROR and sets *result to TRUE or FALSE. TRUE indicates that the input is a permutation (relative to start_value) as defined above.

get_string_why_int_vector_is_not_permutation

DISCLAIMER

This software is not adequatedly tested. It is recomended that results are checked independantly where appropriate.

AUTHOR

Andrew Predoehl

DOCUMENTER