137:只出现一次的数字 II(增加新方式)

src/main/java/leetcode/editor/cn/SingleNumberIi.java

@@ -40,27 +40,34 @@ import java.util.HashMap;
 import java.util.Map;
 
 //137:只出现一次的数字 II
-public class SingleNumberIi{
+public class SingleNumberIi {
     public static void main(String[] args) {
         //测试代码
         Solution solution = new SingleNumberIi().new Solution();
     }
+
     //力扣代码
     //leetcode submit region begin(Prohibit modification and deletion)
-class Solution {
+    class Solution {
         public int singleNumber(int[] nums) {
-        Map<Integer,Integer> map = new HashMap<>();
+//            Map<Integer, Integer> map = new HashMap<>();
-        for (int num :nums){
+//            for (int num : nums) {
-            map.put(num,map.getOrDefault(num,0)+1);
+//                map.put(num, map.getOrDefault(num, 0) + 1);
+//            }
+//            for (int num : map.keySet()) {
+//                if (map.get(num) == 1) {
+//                    return num;
+//                }
+//            }
+//            return 0;
+            int ones = 0, twos = 0;
+            for(int num : nums){
+                ones = ones ^ num & ~twos;
+                twos = twos ^ num & ~ones;
             }
-        for (int num:map.keySet()){
+            return ones;
-            if(map.get(num)==1){
-                return num;
         }
     }
-        return 0;
-    }
-}
 //leetcode submit region end(Prohibit modification and deletion)
 
 }