随机物品权重算法DEMO

package Test;

import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Random;

public class weight {

	
	public static void main(String[] args) throws Exception {
		
		weight weight = new weight();
		//随机源
		Map<Integer,Integer> param = new HashMap<Integer,Integer>();
		
		Map<Integer,Integer> result = new HashMap<Integer,Integer>();
		for(int i=1;i<4;i++){
			param.put(i*1000, i);
		}
		//总权重
		int totalWeights = 0;
		for(Entry<Integer,Integer> entry:param.entrySet()){
			totalWeights +=entry.getKey();
		}
		System.out.println("totalWeights="+totalWeights);
		for(int i=1;i<totalWeights;i++){
			int value = weight.getDataByWeight(totalWeights, param);
			if(!result.containsKey(value)){
				result.put(value, 1);
			}else{
				result.put(value,  result.get(value)+1);
			}
		}
		for(Entry<Integer, Integer> entry:result.entrySet()){
			System.out.println(entry.getKey()+"------"+ Math.round(entry.getValue()/(totalWeights*1.0)*100)+"%");	
			
		}
	}
	
	
	public  static Integer getDataByWeight(int totalWeights,Map<Integer,Integer> param ) throws Exception{
		int random =new Random().nextInt(totalWeights)+1;
		int tmp=0;
		for(Entry<Integer,Integer> entry : param.entrySet()){
			tmp=tmp+entry.getKey();
			if(random<=tmp){
				return entry.getValue();
			}else{
				continue;
			}
		}
		return null;
	}
	
	
}