Pair 값 제거하기

Author: holmir97

SingleNumber.java

@@ -0,0 +1,37 @@
+import java.util.HashSet;
+import java.util.Set;
+
+public class SingleNumber {
+    public int singleNumber(int[] nums) {
+        int sumOfSet = 0, sumOfNums = 0;
+        Set<Integer> set = new HashSet();
+
+        for (int num : nums) {
+            if (!set.contains(num)) {
+                set.add(num);
+                sumOfSet += num;
+            }
+            sumOfNums += num;
+        }
+        return 2 * sumOfSet - sumOfNums;
+
+
+/*      // O(n^2)
+        boolean flag;
+        int result = nums[0];
+
+        for(int i = 0; i<nums.length;i++){
+            flag = false;
+            for(int j = i; j< nums.length; j++) {
+                if (nums[i] == nums[j])
+                    flag = true;
+            }
+
+            if( !flag ){
+                result = nums[i];
+                break;
+            }
+        }
+        return result;*/
+    }
+}