20220520

20220520

加权随机算法实现

package common;lemon.base.Preconditions;
import org.apachemons.math3.util.Pair;import java.util.List;
import java.util.SortedMap;
import java.util.TreeMap;public class WeightRandom<K, V extends Number> {private TreeMap<Double, K> weightMap = new TreeMap<>();/*** @description: 加权随机算法实现* @author 赵璇* @date 2022/5/20 1:31* @version 1.0*/public WeightRandom(List<Pair<K, V>> list) {Preconditions.checkNotNull(list, "list can NOT be null!");for (Pair<K, V> pair : list) {//统一转为doubledouble lastWeight = this.weightMap.size() == 0 ? 0 : this.weightMap.lastKey().doubleValue();//权重累加this.weightMap.Value().doubleValue() + lastWeight, Key());}}public K random() {double randomWeight = this.weightMap.lastKey() * Math.random();SortedMap<Double, K> tailMap = this.weightMap.tailMap(randomWeight, false);return (tailMap.firstKey());}
}

K：KEY，锁定内容使用

V：权值，必须是数值型，而且是包装类

List的remove最佳用法

veIf(next -> ains("#"));