双色球近30期最重复的数字（一段统计双色球历史摇奖记录里每位出现次数的代码）

package testUtility; import java.util.HashMap; import java.util.Iterator; import java.util.Set; import java.util.Vector; import java.util.Map.Entry; public class test_condense { public static void main(String[] args) { HashMap<Integer,Integer> map = new HashMap<Integer,Integer>(); HashMap<Integer,Vector<Integer>> revert = new HashMap<Integer,Vector<Integer>>(); map.put(4, 2); map.put(5, 2); map.put(1, 6); map.put(3, 6); map.put(7, 1); Set<Entry<Integer, Integer>> set = map.entrySet(); Iterator<Entry<Integer, Integer>> itor = set.iterator(); while(itor.hasNext()) { Entry<Integer, Integer> entry = itor.next(); int NumberwithOccurance = entry.getKey(); int Occurance = entry.getValue(); if( revert.containsKey(entry.getValue()) == false) { Vector<Integer> NumberListWithSameOccurance = new Vector<Integer>(); NumberListWithSameOccurance.add(NumberwithOccurance); revert.put(Occurance, NumberListWithSameOccurance); } else { Vector<Integer> existingNumberList = revert.get(Occurance); existingNumberList.add(NumberwithOccurance); revert.put(Occurance, existingNumberList); } } Set<Entry<Integer, Vector<Integer>>> Revertset = revert.entrySet(); Iterator<Entry<Integer, Vector<Integer>>> Revertitor = Revertset.iterator(); while(Revertitor.hasNext()) { Entry<Integer, Vector<Integer>> entry = Revertitor.next(); System.out.println("Occruance: " entry.getKey()); for( int i = 0 ; i < entry.getValue().size(); i ) { System.out.println("Number with same Occurance: " entry.getValue().elementAt(i)); } } } }

这是测试数据：key为双色球号码，value为该号码出现次数，比如(4,2)意思就是4号球出现了两次。

执行代码，输出：

Occruance: 1 Number with same Occurance: 7 Occruance: 2 Number with same Occurance: 4 Number with same Occurance: 5 Occruance: 6 Number with same Occurance: 1 Number with same Occurance: 3

意思是7号球出现了一次，4号球和5号球出现了2次，依次类推。