字节跳动笔试题2020 （抖音电商）

╰+哭是因爲堅強的太久メ 2023-02-26 10:23 20阅读 0赞

题目: 写一个以权重来进行随机分配的程序。

拿到这个题的时候我思考了一下，幸好我之前看了Ribbon 的权重算法。核心的思想就是把所有的权重值加起来，做随机值计算最终确定随机值在权重总值中的位置，从而确定是那个数据。

import java.util.ArrayList;
    import java.util.List;
    
    public class Test12 {
    
        //权重算法
        public Weight getWeight(List<Weight> list){
            int totalWeight = 0;
            for(Weight weight:list){
                totalWeight += weight.getValue();
            }
    
            double random = Math.random();
            Integer weightValue = new Double(Math.ceil(random*totalWeight)).intValue();
            totalWeight = 0;
            for(Weight weight:list){
                totalWeight += weight.getValue();
                if(weightValue - totalWeight<=0){
                    return weight;
                }
            }
            return null;
        }
    
        public static void main(String[] args) {
            Weight weight = new Weight(1,"A");
            Weight weight2 = new Weight(2,"B");
            Weight weight3 = new Weight(3,"C");
    
            List<Weight> list = new ArrayList<>();
            list.add(weight);
            list.add(weight2);
            list.add(weight3);
            Test12 test12 = new Test12();
            Weight returnWeight = test12.getWeight(list);
    
            System.out.println(returnWeight);
    
        }
    }
    
    class Weight{
        private Integer value;
        private String name;
    
        public Weight(Integer value,String name){
            this.value = value;
            this.name = name;
        }
    
        public Integer getValue() {
            return value;
        }
    }

输出结果：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NhaTczOTI5NTczMg_size_16_color_FFFFFF_t_70][]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NhaTczOTI5NTczMg_size_16_color_FFFFFF_t_70]: /images/20230209/a870bda979a34363b1338eedab715a6b.png