js中奖概率算法

// 定义奖品和对应的中奖概率
const prizes = [
  { name: '一等奖', probability: 0.01 },
  { name: '二等奖', probability: 0.05 },
  { name: '三等奖', probability: 0.1 },
  { name: '谢谢参与', probability: 0.84 }
];

// 计算总概率
const totalProbability = prizes.reduce((sum, prize) => sum + prize.probability, 0);

// 中奖概率算法
function drawPrize() {
  const randomNum = Math.random() * totalProbability;
  let cumulativeProbability = 0;

  for (const prize of prizes) {
    cumulativeProbability += prize.probability;
    if (randomNum < cumulativeProbability) {
      return prize.name;
    }
  }

  // 如果由于浮点数精度问题没有中奖，返回最后一个奖品
  return prizes[prizes.length - 1].name;
}

// 测试中奖算法
console.log(drawPrize());