44 lines
1.0 KiB
Java
44 lines
1.0 KiB
Java
package com.thebrokenrail.energonrelics.util;
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import java.util.HashMap;
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import java.util.Map;
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import java.util.Random;
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/**
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* Weighted List
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* @param <T> Entry Type
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*/
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public class WeightedList<T> {
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private final Map<T, Integer> map = new HashMap<>();
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/**
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* Add Entry
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* @param weight Weight
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* @param obj Entry
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*/
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public void add(int weight, T obj) {
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map.put(obj, weight);
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}
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/**
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* Pick Entry
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* @param random Random
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* @return Entry
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*/
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public T pick(Random random) {
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int totalWeight = 0;
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for (Map.Entry<T, Integer> entry : map.entrySet()) {
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totalWeight += entry.getValue();
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}
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int i = random.nextInt(totalWeight + 1);
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int countWeight = 0;
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for (Map.Entry<T, Integer> entry : map.entrySet()) {
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countWeight += entry.getValue();
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if (countWeight >= i) {
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return entry.getKey();
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}
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}
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throw new UnsupportedOperationException();
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}
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}
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