/*# proc: nearest_nbor - returns the location of the point from a list of points# proc:                that is closest to another specified point and returns# proc:                the closest distance.# proc: find_closest_pts - locates the closest pair of points between two# proc:                    specified lists of points.*/#include <stdio.h>#include <values.h>/***********************************************************************//* nearest_nbor nearest neighbor routine *//* Darrin L. Dimmick 5-21-93 *//* Returns the point from esnx and esny which is closest to point_x, point_y *//* in nearest_x, nearest_y *//* esnc is the number of values in ensx. It is also the number of values *//* in esny */  int nearest_nbor(nindex, ndistance, point_x, point_y, esnx, esny, esnc)int *nindex, *ndistance, point_x, point_y, *esnx, *esny, esnc;{  int i, success, ni, nd, dist;  ni = -1;  nd = MAXINT;  for(i = 0; i < esnc; i++){     dist = diff_sq_distance(point_x, point_y, esnx[i], esny[i]);     if (dist < nd){         ni = i;         nd = dist;     } /* if */   } /* for */  *nindex = ni;  *ndistance  = nd;  if (ni < 0)     success = 0;  else     success = 1;  return(success);}/*******************************************************************/find_closest_pts(dcx, dcy, dci, ucx, ucy, uci, dx, dy, dn, ux, uy, un)int *dcx, *dcy, *dci, *ucx, *ucy, *uci;int *dx, *dy, dn;int *ux, *uy, un;{   int di, dist, ui, mindist, min_ui, min_di;   mindist = MAXINT;   for(di = 0; di < dn; di++){      if(!nearest_nbor(&ui, &dist, dx[di], dy[di], ux, uy, un))         fatalerr("find_closest_pts", "nearest nbor not found", NULL);      if(dist < mindist){         mindist = dist;         min_ui = ui;         min_di = di;      }   }   *dcx = dx[min_di];   *dcy = dy[min_di];   *dci = min_di;   *ucx = ux[min_ui];   *ucy = uy[min_ui];   *uci = min_ui;}