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Snail matrix generator

I made a 133 bytes Snail function such as :

snail(4) =

[[1,  2,  3,  4],
12, 13, 14, 5],
11, 16, 15, 6],
10, 9,  8,  7]]

(and the same logic for snail(N), with N >= 0)

 s = function(n,a,d,x,y,c,i){ // a is the result matrix a = [[]]; // d is the direction: right, bottom = 1; left, top = -1 d = 1; // c is the counter value. c = 0; // x and y are the coordinates of the number in the matrix x = 0; y = -1; // for n in [n ... 0] for(; n; n--){ // NB: the following two for loops are merged in the minified code // fill n columns for(i = 0; i < n; i++){ y += d; a[x][y] = ++c; } // fill n-1 lines for(i = 0; i < n - 1; i++){ x += d; if(!a[x]){ a[x] = []; } a[x][y] = ++c; } // change direction d = -d; } return a; }
 s=function(e,c,d,b,f,h,g){c=[[]];d=1;b=h=0;for(f=-1;e;e--){for(g=1;g<2*e;g++)g>e?b+=d:f+=d,c[b]||(c[b]=[]),c[b][f]=++h;d=-d}return c}
 DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE Version 2, December 2004 Copyright (C) 2011 YOUR_NAME_HERE Everyone is permitted to copy and distribute verbatim or modified copies of this license document, and changing it is allowed as long as the name is changed. DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION 0. You just DO WHAT THE FUCK YOU WANT TO.
 { "name": "snail", "description": "generates a snail matrix", "keywords": [ "snail", "matrix" ] }


atk commented Oct 15, 2013

 Save one byte by removing the curly brackets: function(e,c,d,b,f,h,g){for(c=[[]],d=1,b=h=0,f=-1;e;e--)for(g=1;g<2*e;g++)g>e?b+=d:f+=d,c[b]||(c[b]=[]),c[b][f]=++h;d=-d;return c}

hillerstorm commented Oct 23, 2013

 That unfortunately breaks it :/ This one saves 2 bytes by removing brackets (moving d=-d to the last part of the for loop) and moving b=h=0 inside the array definition: function(e,c,d,b,f,h,g){c=[[b=h=0]];d=1;for(f=-1;e;e--,d=-d)for(g=1;g<2*e;g++)g>e?b+=d:f+=d,c[b]||(c[b]=[]),c[b][f]=++h;return c}

hillerstorm commented Oct 23, 2013

 Saving another 2 bytes by changing the check/assignment of c[b]: function(e,c,d,b,f,h,g){c=[[b=h=0]];d=1;for(f=-1;e;e--,d=-d)for(g=1;g<2*e;g++)g>e?b+=d:f+=d,c[b]=c[b]||[],c[b][f]=++h;return c}

hillerstorm commented Oct 23, 2013

 And one more byte (!) by moving to a var-definition instead of placeholder arguments: function(e){var c=[[]],d=1,b=0,h=0,f,g;for(f=-1;e;e--,d=-d)for(g=1;g<2*e;g++)g>e?b+=d:f+=d,c[b]=c[b]||[],c[b][f]=++h;return c}

subzey commented Nov 14, 2013

 -6 bytes: function(e){for(var c=[[]],d=1,b=0,h=0,f=-1,g;e;e--,d=-d)for(g=1;g<2*e;c[b][f]=++h)g++>e?c[b+=d]=c[b]||[]:f+=d;return c}

subzey commented Nov 14, 2013

 I want to ask also, is it necessary c to be [[]], not just []. The only difference is snail(0) would return [] instead of [[]], but as for me, it is even better.
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