##JavaScript (SpiderMonkey) - 118 chars## This version accepts input from stdin and passes the bonus test cases

r=readline()
for(t=0,i=-r;i<r;i++)if(i%2){for(s='',j=-r;j<r;j++){t+=q=i*i+j*j<r*r
s+=q?'*':' '}print(s)}print(t*2/r/r)

Javascript: (削除) 213 (削除ここまで) 163

Updated

r=10;m=Math;a=Array;t=0;l=document;for(i=-r;i<r;i+=2){w=m.floor(m.sqrt(r*r-i*i)*2);t+=w*2;l.writeln(a(m.round(r-w/2)).join(' ')+a(w).join('*'));}l.writeln(t/(r*r))

Nobody said it had to render correctly in the browser - just the output. As such I've removed the pre tags and optimised it further. To view the output you need to view generated source or set your stylesheet accordingly. Pi is less accurate this way, but it's now to spec.

r=10;m=Math;a=Array;t=0;s='';for(i=-r;i<r;i++){w=m.floor((m.sqrt(m.pow(r,2)-m.pow(i,2)))*2);t+=w;if(i%2){z=a(m.round(r-w/2)).join(' ')+a(w).join('*');s+=z+'\n';}}document.write('<pre>'+(s+(t/m.pow(r,2)))+'</pre>')

Unminified:

r=10;
m=Math;
a=Array;
t=0;
s='';
for(i=-r;i<r;i++){
 w=m.floor((m.sqrt(m.pow(r,2)-m.pow(i,2)))*2);
 t+=w;
 if(i%2){
 z=a(m.round(r-w/2)).join(' ')+a(w).join('*');
 s+=z+'\n';
 }
}
document.write('<pre>'+(s+(t/m.pow(r,2)))+'</pre>');

##JavaScript (SpiderMonkey) - 118 chars## This version accepts input from stdin and passes the bonus test cases

r=readline()
for(t=0,i=-r;i<r;i++)if(i%2){for(s='',j=-r;j<r;j++){t+=q=i*i+j*j<r*r
s+=q?'*':' '}print(s)}print(t*2/r/r)

Usage:cat 10 | js thisfile.js -- jsbin preview adds an alias for print/readline so you can view in browser

Javascript: (削除) 213 (削除ここまで) 163

Updated

r=10;m=Math;a=Array;t=0;l=document;for(i=-r;i<r;i+=2){w=m.floor(m.sqrt(r*r-i*i)*2);t+=w*2;l.writeln(a(m.round(r-w/2)).join(' ')+a(w).join('*'));}l.writeln(t/(r*r))

Nobody said it had to render correctly in the browser - just the output. As such I've removed the pre tags and optimised it further. To view the output you need to view generated source or set your stylesheet accordingly. Pi is less accurate this way, but it's now to spec.

r=10;m=Math;a=Array;t=0;s='';for(i=-r;i<r;i++){w=m.floor((m.sqrt(m.pow(r,2)-m.pow(i,2)))*2);t+=w;if(i%2){z=a(m.round(r-w/2)).join(' ')+a(w).join('*');s+=z+'\n';}}document.write('<pre>'+(s+(t/m.pow(r,2)))+'</pre>')

Unminified:

r=10;
m=Math;
a=Array;
t=0;
s='';
for(i=-r;i<r;i++){
 w=m.floor((m.sqrt(m.pow(r,2)-m.pow(i,2)))*2);
 t+=w;
 if(i%2){
 z=a(m.round(r-w/2)).join(' ')+a(w).join('*');
 s+=z+'\n';
 }
}
document.write('<pre>'+(s+(t/m.pow(r,2)))+'</pre>');

##JavaScript (SpiderMonkey) - 157 chars## This version accepts input from stdin and passes the test cases

r=readline()
p=print
a=Array
m=Math
for(t=0,i=-r+1;i<r;i++)if(i%2){t+=j=m.floor(m.sqrt(r*r-i*i))*2+1
p(a(m.round(r-j/2)).join(' ')+a(j).join('*'))}p(t*2/r/r)

Javascript: (削除) 213 (削除ここまで) 163

Updated

r=10;m=Math;a=Array;t=0;l=document;for(i=-r;i<r;i+=2){w=m.floor(m.sqrt(r*r-i*i)*2);t+=w*2;l.writeln(a(m.round(r-w/2)).join(' ')+a(w).join('*'));}l.writeln(t/(r*r))

Nobody said it had to render correctly in the browser - just the output. As such I've removed the pre tags and optimised it further. To view the output you need to view generated source or set your stylesheet accordingly. Pi is less accurate this way, but it's now to spec.

r=10;m=Math;a=Array;t=0;s='';for(i=-r;i<r;i++){w=m.floor((m.sqrt(m.pow(r,2)-m.pow(i,2)))*2);t+=w;if(i%2){z=a(m.round(r-w/2)).join(' ')+a(w).join('*');s+=z+'\n';}}document.write('<pre>'+(s+(t/m.pow(r,2)))+'</pre>')

Unminified:

r=10;
m=Math;
a=Array;
t=0;
s='';
for(i=-r;i<r;i++){
 w=m.floor((m.sqrt(m.pow(r,2)-m.pow(i,2)))*2);
 t+=w;
 if(i%2){
 z=a(m.round(r-w/2)).join(' ')+a(w).join('*');
 s+=z+'\n';
 }
}
document.write('<pre>'+(s+(t/m.pow(r,2)))+'</pre>');

##JavaScript (SpiderMonkey) - 118 chars## This version accepts input from stdin and passes the bonus test cases

r=readline()
for(t=0,i=-r;i<r;i++)if(i%2){for(s='',j=-r;j<r;j++){t+=q=i*i+j*j<r*r
s+=q?'*':' '}print(s)}print(t*2/r/r)

Javascript: (削除) 213 (削除ここまで) 163

Updated

r=10;m=Math;a=Array;t=0;l=document;for(i=-r;i<r;i+=2){w=m.floor(m.sqrt(r*r-i*i)*2);t+=w*2;l.writeln(a(m.round(r-w/2)).join(' ')+a(w).join('*'));}l.writeln(t/(r*r))

Nobody said it had to render correctly in the browser - just the output. As such I've removed the pre tags and optimised it further. To view the output you need to view generated source or set your stylesheet accordingly. Pi is less accurate this way, but it's now to spec.

r=10;m=Math;a=Array;t=0;s='';for(i=-r;i<r;i++){w=m.floor((m.sqrt(m.pow(r,2)-m.pow(i,2)))*2);t+=w;if(i%2){z=a(m.round(r-w/2)).join(' ')+a(w).join('*');s+=z+'\n';}}document.write('<pre>'+(s+(t/m.pow(r,2)))+'</pre>')

Unminified:

r=10;
m=Math;
a=Array;
t=0;
s='';
for(i=-r;i<r;i++){
 w=m.floor((m.sqrt(m.pow(r,2)-m.pow(i,2)))*2);
 t+=w;
 if(i%2){
 z=a(m.round(r-w/2)).join(' ')+a(w).join('*');
 s+=z+'\n';
 }
}
document.write('<pre>'+(s+(t/m.pow(r,2)))+'</pre>');

##JavaScript (SpiderMonkey) - 159 chars## This version accepts input from stdin and passes the test cases

r=readline()
p=print
a=Array
m=Math
for(t=0,i=-r+1;i<r;i++)if(i%2){t+=j=m.floor(m.sqrt(r*r-i*i))*2+1
p(a(m.round(r-j/2)).join(' ')+a(j).join('*'))}p(t*2/(r*r))

Javascript: (削除) 213 (削除ここまで) 163

Updated

r=10;m=Math;a=Array;t=0;l=document;for(i=-r;i<r;i+=2){w=m.floor(m.sqrt(r*r-i*i)*2);t+=w*2;l.writeln(a(m.round(r-w/2)).join(' ')+a(w).join('*'));}l.writeln(t/(r*r))

Nobody said it had to render correctly in the browser - just the output. As such I've removed the pre tags and optimised it further. To view the output you need to view generated source or set your stylesheet accordingly. Pi is less accurate this way, but it's now to spec.

r=10;m=Math;a=Array;t=0;s='';for(i=-r;i<r;i++){w=m.floor((m.sqrt(m.pow(r,2)-m.pow(i,2)))*2);t+=w;if(i%2){z=a(m.round(r-w/2)).join(' ')+a(w).join('*');s+=z+'\n';}}document.write('<pre>'+(s+(t/m.pow(r,2)))+'</pre>')

Unminified:

r=10;
m=Math;
a=Array;
t=0;
s='';
for(i=-r;i<r;i++){
 w=m.floor((m.sqrt(m.pow(r,2)-m.pow(i,2)))*2);
 t+=w;
 if(i%2){
 z=a(m.round(r-w/2)).join(' ')+a(w).join('*');
 s+=z+'\n';
 }
}
document.write('<pre>'+(s+(t/m.pow(r,2)))+'</pre>');

##JavaScript (SpiderMonkey) - 157 chars## This version accepts input from stdin and passes the test cases

r=readline()
p=print
a=Array
m=Math
for(t=0,i=-r+1;i<r;i++)if(i%2){t+=j=m.floor(m.sqrt(r*r-i*i))*2+1
p(a(m.round(r-j/2)).join(' ')+a(j).join('*'))}p(t*2/r/r)

Javascript: (削除) 213 (削除ここまで) 163

Updated

r=10;m=Math;a=Array;t=0;l=document;for(i=-r;i<r;i+=2){w=m.floor(m.sqrt(r*r-i*i)*2);t+=w*2;l.writeln(a(m.round(r-w/2)).join(' ')+a(w).join('*'));}l.writeln(t/(r*r))

Nobody said it had to render correctly in the browser - just the output. As such I've removed the pre tags and optimised it further. To view the output you need to view generated source or set your stylesheet accordingly. Pi is less accurate this way, but it's now to spec.

r=10;m=Math;a=Array;t=0;s='';for(i=-r;i<r;i++){w=m.floor((m.sqrt(m.pow(r,2)-m.pow(i,2)))*2);t+=w;if(i%2){z=a(m.round(r-w/2)).join(' ')+a(w).join('*');s+=z+'\n';}}document.write('<pre>'+(s+(t/m.pow(r,2)))+'</pre>')

Unminified:

r=10;
m=Math;
a=Array;
t=0;
s='';
for(i=-r;i<r;i++){
 w=m.floor((m.sqrt(m.pow(r,2)-m.pow(i,2)))*2);
 t+=w;
 if(i%2){
 z=a(m.round(r-w/2)).join(' ')+a(w).join('*');
 s+=z+'\n';
 }
}
document.write('<pre>'+(s+(t/m.pow(r,2)))+'</pre>');