window.AStar = {};
(function(aStar){

	//start:起始节点[i,j] ， end:最终节点[i,j]  map:地图数据(2d)arr，marker:可以通过的标识（例子用的是1）
	aStar.find_path = function(start,end,map,marker){
		var open = [];
		var close = [];

		var s_p = start;
		var e_p = end;
		var map_arr = map;
		var tra_marker = marker;
	
		var G = 0;
		var H = 0;
		var F = 0;

		//加入起始节点  [x, y , G ,F ,father]
		open.push([s_p[0],s_p[1],0,(Math.abs(e_p[0]-s_p[0]) + Math.abs(e_p[1]-s_p[1])),null]);

		return function(obj){
			//重拍，取最小的一个
			var count = 0;
			for(var i = obj[0]-1,ilen = i+3 ; i < ilen ; i++){
				for(var j = obj[1]-1,jlen = j+3 ;j < jlen; j++){
					//遍历周围八节点,排除自己
					if(i == obj[0] && j == obj[1])
						continue;
					//排除穿越的情况
					if(!((i == obj[0] ) || ( j == obj[1])) && ( map_arr[i] && map_arr[obj[0]] && map_arr[i][obj[1]] != tra_marker && map_arr[obj[0]][j] != tra_marker))
						continue;
					if(i == e_p[0] && j == e_p[1]){
						open.push([i,j,G,F,obj]);
						var ways = [];
						var ele = obj;
						do{
							ways.unshift(ele);
							ele = ele[4];
						}while(ele[4] != null);
						return ways;
					}
					
					if(map_arr[i] && map_arr[i][j] && map_arr[i][j] == tra_marker && is_exist(open,[i,j]) == -1 && is_exist(close,[i,j]) == -1){
						G = ( i == obj[0] ) || ( j == obj[1] ) ? obj[2]+1.0 : obj[2]+1.4 ;				
						H = Math.sqrt((e_p[0] - i)*(e_p[0] - i) + (e_p[1] - j)*(e_p[1] - j));
						F = G + H;

						open.push([i,j,G,F,obj]);
						count++;
					}
				}
			}
			close.push(open.shift());
			var o;
			if(open[0] && open[0][4] == obj[4]){
				o = count == 0 ? get_other(open,obj) : (arr_sort(open),open[0]);
			}else{
				o = (arr_sort(open),open[0]);
			}
			
			if(o){
				return arguments.callee(o);
			}else{
				return [];
			}
		}(open[0])
	}

	
	//获取其他节点
	var get_other = function(arr,o){
		var a = [];
		for(var i = 0 ; i < arr.length ; i++){
			if(o && arr[i][4] == o[4]){
				return arr[i];
			}
		}
		if(o[4]){
			return arguments.callee(o[4]);
		}else{
			return null;
		}
	}

	
	//对数组进行重排列
	var arr_sort = function(){
		function s(a,b){
			return a[3] - b[3];
		}
		return function(arr){
			arr.sort(s);
		}
	}();

	//数组中是否存在此元素
	var is_exist = function(arr,p){
		for(var i = 0 ; i < arr.length ; i++){
			if(arr[i][0] == p[0] && arr[i][1] == p[1]){
				return i;
			}
		}
		return -1;
	}
})(window.AStar)

<script src="a_star.js"></script>
<link rel="stylesheet" type="text/css" href="reset.css" />
<script>
	var state = 1;
	var w = 20;
	var h = 10;
	var map_arr = [];
	var start,end;

	window.onload = function(){
		var map = document.getElementById("map");
		var arr = [];
		
		
		arr.push("<table border=\"1\">");
		for(var i = 0 ; i < h ; i++){
			arr.push("<tr>");
			if(!map_arr[i]) map_arr[i] = [];
			for(var j = 0 ; j < w ;j++){
				arr.push("<td id=\""+i+"-"+j+"\" style=\"width:50px;height:50px;border:1px solid #000\" onclick=\"td(" + i + "," + j + ")\"></td>");
				map_arr[i][j] = 1;
			}
			arr.push("</tr>");
		}
		arr.push("</table>");
		map.innerHTML = arr.join("");
	}

	function td(x,y){
		var e = document.getElementById( x + "-" + y);
		switch(state){
			case 1:
				start = [x,y];
				e.style.backgroundColor = "#0f0";
				break;
			case 2:
				end = [x,y];
				e.style.backgroundColor = "#f00";
				break;
			case 3:
				e.style.backgroundColor = "#000";
				map_arr[x][y] = 0;
				break;
		}
		
	}

	function changeS(value){
		state = value;
	}

	function find_path(){
		
		var ways = AStar.find_path(start,end,map_arr,1);
		if(ways.length == 0 ){
			alert("no ways!~~~");
			return ;
		}
		for(var i = 0;i < ways.length; i++){
			 var e = docume