@@ -3,17 +3,34 @@ private static class ListNode {
33 int val ;
44 ListNode next ;
55 ListNode (int val ) { this .val = val ; }
6+ 7+ @ Override
8+ public String toString () {
9+ if (next == null ) return "ListNode{val=" + val + ", next=null}" ;
10+ return "ListNode{" +
11+ "val=" + val +
12+ ", next=" + next +
13+ '}' ;
14+ }
15+ }
16+ 17+ public static void main (String [] args ) {
18+ ListNode head = new ListNode (1 );
19+ head .next = new ListNode (2 );
20+ head .next .next = new ListNode (3 );
21+ head .next .next .next = new ListNode (4 );
22+ head .next .next .next .next = new ListNode (5 );
23+ System .out .println (reverseBetween (head , 2 , 4 ));
624 }
725
8- public ListNode reverseBetween (ListNode head , int leftVal , int rightVal ) {
26+ public static ListNode reverseBetween (ListNode head , int leftVal , int rightVal ) {
927 if (leftVal == rightVal ) return head ;
1028
1129 ListNode sentinelHead = new ListNode (-1000 );
1230 sentinelHead .next = head ;
1331 ListNode beforeLeft = getNodeBefore (sentinelHead , leftVal );
1432 System .out .println (beforeLeft .val );
1533 ListNode left = beforeLeft .next ;
16- // ListNode afterRight = getNodeAfter(sentinelHead, rightVal);
1734 ListNode a = beforeLeft .next , b = a .next , c = b .next ;
1835
1936 while (c != null && b .val != rightVal ) {
@@ -23,24 +40,16 @@ public ListNode reverseBetween(ListNode head, int leftVal, int rightVal) {
2340 b = c ;
2441 c = c .next ;
2542 }
26- a .next = null ;
2743 b .next = a ;
2844 beforeLeft .next = b ;
2945 left .next = c ;
3046 return sentinelHead .next ;
3147 }
3248
33- private ListNode getNodeBefore (ListNode head , int value ) {
49+ private static ListNode getNodeBefore (ListNode head , int value ) {
3450 while (head != null && head .next != null && head .next .val != value ) {
3551 head = head .next ;
3652 }
3753 return head ;
3854 }
39- 40- private ListNode getNodeAfter (ListNode head , int value ) {
41- while (head != null && head .val != value ) {
42- head = head .next ;
43- }
44- return head .next ;
45- }
4655}
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