#include "cstd.h"

void acd_2d_2(float ** uc, 
	      float ** up, 
	      float ** csq, 
	      int * s, 
	      int * e, 
	      float c0, 
	      float * c1) {

  int i0, i1;
  for (i1=s[1]; i1<=e[1]; i1++) {
    for (i0=s[0]; i0<=e[0]; i0++) {
        float lap=(c0*uc[i1][i0]+
                   c1[0]*(uc[i1][i0+1]+uc[i1][i0-1])+
                   c1[1]*(uc[i1+1][i0]+uc[i1-1][i0]));
        up[i1][i0] = 2.0*uc[i1][i0] - up[i1][i0] +
                csq[i1][i0] * lap;
    }
  }

  /* boundary condns: up[-1][i]=0 etc. these do not need to be enforced as they are 
  // a by-product of initialization and involve only non-updated allocated array 
  // entries */
}