九宫格跑马灯

```

var begin=0

function op(num,class_name){

if(num>$("li").size()-1){num=0}

$("ul").children("li").eq(num).addClass(class_name).siblings("li").removeClass(class_name);

num++;

return num

}

var num_r=parseInt( Math.random()*10+32);

console.log(num_r) //控制几率

function run(time){

if(time<=0){return false}

var time_over=setTimeout(function(){

begin=op(begin,"gg")

num_r=num_r-1;

run(num_r)

},50)

}

run()

```