控制随机数生成概率的一种解决方法

问题描述：

我想生成10个数，范围为0~9，其中生成的数以及生成的概率如下

0------------10%

1------------20%

2------------5%

3------------30%

4------------5%

5------------5%

6------------5%

7------------10%

8------------5%

9------------5%

那怎么做呢？

var id:int;
var random:Number = Math.random();
if(random < 0.1)
id = 0;
else if(random < 0.3)
id = 1;
else if(random < 0.35)
id = 2;
else if(random < 0.65)
id = 3
else if(random < 0.7)
id = 4;
else if(random < 0.75)
id = 5;
else if(random < 0.8)
id = 6;
else if(random < 0.9)
id = 7;
else if(random < 0.95)
id = 8;
else if(random < 1)
id = 9;

当0<=random<0.1(区间跨度0.1)             id = 0;

当0.1<=random<0.3(区间跨度0.2)            id = 1;

当0.3<=random<0.35(区间跨度0.05)      id = 2;

当0.35<=random<0.65(区间跨度0.3)        id = 3;

当0.65<=random<0.7(区间跨度0.05)       id = 4;

当0.7<=random<0.75(区间跨度0.05)       id = 5;

当0.75<=random<0.8(区间跨度0.05)       id = 6

当0.8<=random<0.9(区间跨度0.1)           id = 7

当0.9<=random<0.95(区间跨度0.05)     id = 8

当0.95<=random<1(区间跨度0.05)         id =9