Created
July 12, 2012 07:51
-
-
Save tiye/3096526 to your computer and use it in GitHub Desktop.
双平衡三进制, IV 象限素数分布
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| <!doctype html> | |
| <html> | |
| <head> | |
| <title> | |
| 33 | |
| </title> | |
| <script src="33.js"></script> | |
| </head> | |
| <body> | |
| <canvas id="canvas"></canvas> | |
| </body> | |
| </html> |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| window.onload=start; | |
| function start(){ | |
| var n=prompt(); | |
| var canvas=document.getElementById('canvas'); | |
| var ctx=canvas.getContext('2d'); | |
| canvas.setAttribute('width',n); | |
| canvas.setAttribute('height',n); | |
| var arr=[]; | |
| for(var i=0;i<n;i++){ | |
| arr[i]=[]; | |
| for(var j=0;j<n;j++){ | |
| arr[i][j]=0;}} | |
| var edge=Math.ceil(n*Math.sqrt(2)/2+n/2)+4; | |
| for(var x=1;x<n;x++){ | |
| for(var y=0;y<n;y++){ | |
| if(x==1&&y==0){continue;} | |
| if(arr[x][y]==1){continue;} | |
| for(var rho_step=1;;rho_step++){ | |
| var rho_x=rho_step*x; | |
| var rho_y=rho_step*y; | |
| if(rho_step>1){ | |
| if(rho_x<n&&rho_y<n){ | |
| arr[rho_x][rho_y]=1;}} | |
| if(rho_x>edge){break;} | |
| if(rho_y>edge){break;} | |
| var left_x=rho_x; | |
| var left_y=rho_y; | |
| //console.log(left_x,left_y); | |
| while(1){ | |
| left_x-=y; | |
| left_y+=x; | |
| if(left_x<0){break;} | |
| if(left_y>=n){break;} | |
| if(left_x<n&&left_y>=0){ | |
| arr[left_x][left_y]=1;}} | |
| var right_x=rho_x; | |
| var right_y=rho_y; | |
| while(1){ | |
| right_x+=y; | |
| right_y-=x; | |
| if(right_x>=n){break;} | |
| if(right_y<0){break;} | |
| if(right_x>=0&&right_y<n){ | |
| arr[right_x][right_y]=1;}}}}} | |
| //console.log(arr); | |
| for(var x=0;x<n;x++){ | |
| for(var y=0;y<n;y++){ | |
| if(arr[y][x]==0){ | |
| ctx.fillRect(x,y,1,1);}}}} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment