1 files changed, 108 insertions, 0 deletions
diff --git a/jscalc/chainreaction.js b/jscalc/chainreaction.js
new file mode 100644
index 0000000..b1ffbbe
--- /dev/null
+++ b/jscalc/chainreaction.js
@@ -0,0 +1,108 @@
+#!/usr/bin/env node
+var b=[[1,2,1],[1,4,2],[1,2,1]];
+
+S=JSON.stringify.bind(JSON);
+Eq=function(a,b){return a.map(function(r,i){return r.map(function(v,j){return b[i][j]==v;}).reduce(function(a,b){return a&&b;});}).reduce(function(a,b){return a&&b;});};
+
+printboard=function(b){
+	if(!Array.isArray(b)){
+		console.log(b);
+		return;
+	}
+	b.forEach(function(r){
+		console.log(r.join(" "));
+	});
+};
+
+evolve=function(b){
+	var w=b[0].length,h=b.length,x,y,nnei,dif;
+	var nb=b.map(function(r){return r.slice(0);});
+	for(y=0;y<h;y++)for(x=0;x<w;x++){
+		nnei=(x>0)+(x<w-1)+(y>0)+(y<h-1);
+		if(b[y][x]>=nnei){
+			dif=~~(b[y][x]/nnei);
+			nb[y][x]-=dif*nnei;
+			if(x>0)nb[y][x-1]+=dif;
+			if(y>0)nb[y-1][x]+=dif;
+			if(x<w-1)nb[y][x+1]+=dif;
+			if(y<h-1)nb[y+1][x]+=dif;
+		}
+	}
+	return nb;
+};
+
+fullevolve=function(b){
+	var nb,lst,i;
+	nb=evolve(b);
+	lst=[b,nb];
+	while(true){
+		b=nb;
+		nb=evolve(nb);
+		if(Eq(b,nb))return lst;
+		for(i=0;i<lst.length;i++)if(Eq(nb,lst[i]))return lst.concat([nb,Infinity]);
+		lst.push(nb);
+	}
+};
+
+repcheck=function(b){
+	var nb,lst,i;
+	nb=evolve(b);
+	lst=[b,nb];
+	while(true){
+		b=nb;
+		nb=evolve(nb);
+		if(Eq(b,nb))return false;
+		for(i=0;i<lst.length;i++)if(Eq(nb,lst[i]))return true;
+		lst.push(nb);
+	}
+};
+
+convform=function(a,w,h){
+	var y,res;
+	res=new Array(h);
+	for(y=0;y<h;y++)res[y]=a.slice(w*y,w*y+w);
+	return res;
+};
+
+solvewh=function(w,h){
+	var maxmap,x,y,stk,i;
+	var res=[];
+	maxmap=new Array(w*h);
+	maxmap[0]=maxmap[w-1]=maxmap[w*(h-1)]=maxmap[w*(h-1)+w-1]=2;
+	for(x=1;x<w-1;x++)maxmap[x]=maxmap[w*(h-1)+x]=3;
+	for(y=1;y<h-1;y++)maxmap[w*y]=maxmap[w*y+w-1]=3;
+	for(y=1;y<h-1;y++)for(x=1;x<w-1;x++)maxmap[w*y+x]=4;
+	console.log("maxmap="+S(maxmap));
+	stk=new Array(w*h).fill(0);
+	while(true){
+		//console.log("stk="+S(stk));
+		for(i=0;i<w*h;i++){
+			stk[i]++;
+			if(repcheck(convform(stk,w,h)))res.push(convform(stk,w,h));
+			stk[i]--;
+		}
+		stk[stk.length-1]++;
+		while(stk[stk.length-1]>=maxmap[stk.length-1]){stk.pop();stk[stk.length-1]++;}
+		if(stk.length==0)break;
+		while(stk.length<w*h)stk.push(0);
+	}
+	return res;
+};
+
+solveallminimal=function(w,h){
+	var res=solvewh(w,h);
+	var ressorted=res.map(function(b){return [b,b.reduce(function(a,b){return a+b.reduce(function(a,b){return a+b;});},0)];}).sort(function(a,b){return a[1]-b[1];});
+	var smallest=ressorted.filter(function(r){return r[1]==ressorted[0][1];}).map(function(r){return r[0];});
+	return smallest;
+};
+
+printboardlist=function(blist){
+	blist.forEach(function(b){printboard(b);console.log();});
+};
+
+printallminimal=function(w,h){printboardlist(solveallminimal(w,h));}
+
+printallminimal(3,3);
+
+
+require("repl").start({prompt:"> ",useGlobal:true}).context=this;