invrse.c

http://www.math.tu-berlin.de/~bolle/SPARSPAK/index-e.html

#include <sparspak.h>

/*****************************************************************************/
/* 'invrse' computes the inverse permutation of the permuation vector 'perm',*/
/* i.e. if 1,2,...,n are mapped onto perm[1],perm[2],...,perm[n], then       */
/* invp[perm[1]],invp[perm[2],...,invp[perm[n]] are mapped back to 1,2,...,n */
/* In C, 'perm, invp' have SUBSCRIPTS 0,1,2,...,*n-1, while the components of*/
/* 'perm','invp' have CONTENTS between 1 and *n.                             */
/*****************************************************************************/
void invrse(int *n, int *perm, int *invp)

{
   int   i;

   for (i=0; i<*n; i++)
       invp[perm[i]-1]=i+1;
} /* end invrse */