Winner Paulo Uribe (turbf1)

2002-05-23 00:00:00 UTC

# try12

by gaof

Status: Passed
Results: Average strain = 2032.285
CPU Time: 171.107
Score: 7809.33
Submitted at: 2002-05-23 10:30:32 UTC
Scored at: 2002-05-23 12:40:12 UTC

Current Rank: 47th
Based on: try11 (diff)
Basis for: trymore1 (diff)
Basis for: trymore2 (diff)
Basis for: trymore3 (diff)
...and 9 others.

Code
```function xy = solver(kd,bx)
npts = length(kd);
if ~any(kd(:)>0),
xy = zeros(npts,2);
return
end
dx=bx(2);
dy=bx(4);
D=dx+1i*dy;
pm=D/2;
xy=zeros(1,npts)+pm;

d=0.1*max(dx,dy);
x=0:d:dx;
y=0:d:dy;
[xx,yy] = ndgrid(x,1i*y);
[nx,ny]=size(xx);
onesx=ones(1,nx);
onesy=ones(1,ny);
XX=xx(:)+yy(:);

dr=abs(D);
kd(find(kd>dr))=dr;

S=(kd-eye(npts))>=0;
nX=length(XX);
xOnes=ones(nX,1);
xZeros=zeros(nX,1);
start=1;
iones=ones(1,npts);
sCut = 1;

olds = 1.0e30;
iterbigmax = 1;

for iterbig = 1:iterbigmax
[dum,p]=sort(-max(kd));
S=S(p,p);
kd=kd(p,p);
[v,w]=sort(p);
xxx=10;
if npts<50
xxx=11;
end;
for iter=1:xxx

for index = 1:npts
I = find(S(:,index));
if ~isempty(I)
st = sum(abs(abs(XX(:,ones(size(I)))-xy(xOnes,I))-kd(xZeros+index,I)),2);
[null,minloc] = min(st);
xy(index) = XX(minloc);
end
end
[s,M]=findstrain(S,xy,kd);
if((abs(s-olds)/(s+1)) < 0.002) | s < sCut
break;
end
olds = s;
end
xy=xy.';
xy=xy(w,:);
kd=kd(w,w);
S=S(w,w);

olds = 1.0e50;
oldxy = xy;
alpha = 1;

for iter=1:40
[s,M]=findstrain(S,xy,kd);
if( iter > 5 & abs(s-olds) / (s+1) < 0.0001 ) | s < sCut
xy = oldxy;
break;
end

if( s > olds )
xy = oldxy;
break;
end
oldxy = xy;
olds = s;
for indx = 1:npts
I = find(S(:,index)>0);
dX=xy(I)-xy(indx);
Dx=mean(dX.*(1-kd(I,index)./(abs(dX)+eps)));
%            Dx=mean(dX./(abs(dX)+eps) .* M(I,indx));

xy(indx) = xy(indx) + alpha*Dx;
xy(indx) = min(dx,max(0,real(xy(indx))))+1i*min(dy,max(0,imag(xy(indx))));
end
end

if( iterbig < iterbigmax )
xy=xy.';
end
end

alpha = 0.1;

[objnew,strainMatrix]=findstrain(S,xy,kd);
obj(1) = objnew;
xybig(:,1) = xy;

[s,sM,dM]=findstrain(S,xy,kd);

xy = xy - alpha  * gradient;
xy = min(max(real(xy),bx(1)),bx(2)) + j * min(max(imag(xy),bx(3)),bx(4));
[objnew,strainMatrix]=findstrain(S,xy,kd);

obj(ij) = objnew;
xybig(:,ij) = xy;
if( obj(ij) > obj(ij-1) )
xy = xybig(:,ij-1);
alpha = alpha / 10;
else
alpha = alpha * 2;
end
[bestobj,index] = min(obj);
if( ij > 3 & index < 2 ) | bestobj < sCut
break
end
end
[bestobj,index] = min(obj);
xy = xybig(:,index);
xy=[real(xy) imag(xy)];

function [s,strainMatrix,dX]=findstrain(S,xy,kd)
sI=find(S);
strainMatrix=S;
dX=S;
[X1,X2]=meshgrid(xy);
dX(sI)=X1(sI)-X2(sI);
strainMatrix(sI) = abs(dX(sI))-kd(sI);
s = sum(abs(strainMatrix(sI)));
```