/*****************************************************************************
** banzhaf.h = header file for Banzhaf power index computations
**
** Original version: Mark A. Livingston, 24 Dec 95
** Dept. of Computer Science, Univ. of North Carolina
**
** Modification: 05 May 2000 (Added qualified majority switch)
** Hewlett-Packard Laboratories, Palo Alto, California
**
** Copyright (C) 1995--2000, Mark A. Livingston, The University of North
** Carolina at Chapel Hill, Hewlett-Packard Company
**
** Type declarations needed for computation of Banzhaf power index for a
** voting block.
*****************************************************************************/

/* Boolean type and constants */
#ifndef False
#define False 0
#endif
#ifndef True
#define True !False
#endif
typedef int Boolean;

/* some simple constants */
#define BUFLEN  256
#define NAMELEN  81

/* Main structure for organizing data */
typedef struct {
  /* static data, read from file */
  char    *name;   /* of block */
  int      pop;    /* ulation */
  int      weight; /* number of votes for this block */

  /* first group used for counting of coalitions */
  Boolean  member;  /* are we in the current 'yea' coalition? */
  unsigned long     power;   /* current number of 'critical' coalition memberships */
  double   Pb_chng; /* probability of block changing election result */

  /* second group used for computations done with Stirling's approximation */
  double   Pp_chng; /* probability of changing block's decision */

  /* putting it all together */
  double   ppc;     /* power per capita, computed by either method */
  double   pr;      /* power ratio, eventually normalized to be relative to
		       power of citizens with the weakest voting strength */

} Block;

/* Function declarations */
int banzhafReadBlocks( char *fname, Block **bl );
void banzhafSetMajority( int value );
Boolean banzhafNextCoalition( Block *bl, int ct, Boolean verbose );
Boolean banzhafHasCritical( Block *bl, int ct );
void banzhafCountCritical( Block *bl, int ct );
void banzhafComputeRatios( Block *bl, int ct );
void banzhafPrintTable( Block *bl, int ct );

#define Swap( a, b, t ) { t = b; b = a; a = t; }