getRandomListByWeight<T> static method

List<Map<T, int>> getRandomListByWeight<T>(List<Map<T, int>> list, int count)

按权重返回对应需要个数的数组

Implementation

static List<Map<T, int>> getRandomListByWeight<T>(List<Map<T, int>> list, int count)
{
  if (count <= 0)
  {
    throw Exception("list.count不能 小于等于 = ");
  }
  if (list.length <= count)
  {
    return list;
  }
  //计算权重总和
  var totalWeights = list.sum<int>((ls)=>ls.values.sum());
  //随机赋值权重
  Random ran = OdinRandomUtils.createRandom();  //GetRandomSeed()随机种子，防止快速频繁调用导致随机一样的问题
  var weightlst = <Map<T, int>>[];
  for (int i = 0; i < list.length; i++)
  {
    int w = (list[i].values.first + 1) + ran.odinNextInt(totalWeights);   // （权重+1） + 从0到（总权重-1）的随机数
    weightlst.add({list[i].keys.first:w});
  }
  //排序
  weightlst.sort((kvp1,kvp2)=>kvp2.values.first - kvp1.values.first);
  return weightlst.take(count).toList();
}