add a solution for 86

fishercoder1534 · fishercoder1534 · commit 81dacbe4eef6 · 2021-04-14T07:29:44.000-07:00
diff --git a/src/main/java/com/fishercoder/solutions/_86.java b/src/main/java/com/fishercoder/solutions/_86.java
@@ -2,6 +2,9 @@
 
 import com.fishercoder.common.classes.ListNode;
 
+import java.util.ArrayList;
+import java.util.List;
+
 public class _86 {
     public static class Solution1 {
         public ListNode partition(ListNode head, int x) {
@@ -27,4 +30,32 @@ public ListNode partition(ListNode head, int x) {
             return left.next;
         }
     }
+
+    public static class Solution2 {
+        public ListNode partition(ListNode head, int x) {
+            List<Integer> first = new ArrayList<>();
+            List<Integer> last = new ArrayList<>();
+            while (head != null) {
+                if (head.val < x) {
+                    first.add(head.val);
+                } else {
+                    last.add(head.val);
+                }
+                head = head.next;
+            }
+            ListNode pre = new ListNode(-1);
+            ListNode tmp = pre;
+            int i = 1;
+            int j = 0;
+            while (i < first.size() || j < last.size()) {
+                if (i < first.size()) {
+                    tmp.next = new ListNode(first.get(i++));
+                } else if (j < last.size()) {
+                    tmp.next = new ListNode(last.get(j++));
+                }
+                tmp = tmp.next;
+            }
+            return pre.next;
+        }
+    }
 }
diff --git a/src/test/java/com/fishercoder/_86Test.java b/src/test/java/com/fishercoder/_86Test.java
@@ -12,19 +12,22 @@
 
 public class _86Test {
     private static _86.Solution1 solution1;
+    private static _86.Solution2 solution2;
     private static ListNode head;
     private static ListNode expected;
 
     @BeforeClass
     public static void setup() {
         solution1 = new _86.Solution1();
+        solution2 = new _86.Solution2();
     }
 
     @Test
     public void test1() {
         head = LinkedListUtils.createSinglyLinkedList(Arrays.asList(1, 4, 3, 2, 5, 2));
         expected = LinkedListUtils.createSinglyLinkedList(Arrays.asList(1, 2, 2, 4, 3, 5));
         assertEquals(expected, (solution1.partition(head, 3)));
+        assertEquals(expected, (solution2.partition(head, 3)));
     }
 
 }

Original file line number	Diff line number	Diff line change
`@@ -12,19 +12,22 @@`
`12`	`12`
`13`	`13`	`public class _86Test {`
`14`	`14`	`private static _86.Solution1 solution1;`
	`15`	`+ private static _86.Solution2 solution2;`
`15`	`16`	`private static ListNode head;`
`16`	`17`	`private static ListNode expected;`
`17`	`18`
`18`	`19`	`@BeforeClass`
`19`	`20`	`public static void setup() {`
`20`	`21`	`solution1 = new _86.Solution1();`
	`22`	`+ solution2 = new _86.Solution2();`
`21`	`23`	`}`
`22`	`24`
`23`	`25`	`@Test`
`24`	`26`	`public void test1() {`
`25`	`27`	`head = LinkedListUtils.createSinglyLinkedList(Arrays.asList(1, 4, 3, 2, 5, 2));`
`26`	`28`	`expected = LinkedListUtils.createSinglyLinkedList(Arrays.asList(1, 2, 2, 4, 3, 5));`
`27`	`29`	`assertEquals(expected, (solution1.partition(head, 3)));`
	`30`	`+ assertEquals(expected, (solution2.partition(head, 3)));`
`28`	`31`	`}`
`29`	`32`
`30`	`33`	`}`