update 19

fishercoder1534 · fishercoder1534 · commit 7f36bb4f28d2 · 2024-07-08T12:15:04.000-07:00
diff --git a/src/main/java/com/fishercoder/solutions/firstthousand/_19.java b/src/main/java/com/fishercoder/solutions/firstthousand/_19.java
@@ -75,10 +75,10 @@ public ListNode removeNthFromEnd(ListNode head, int n) {
     public static class Solution3 {
         //a more concise version using the same idea
         public ListNode removeNthFromEnd(ListNode head, int n) {
-            ListNode dummy = new ListNode(-1);
-            dummy.next = head;
-            ListNode slow = dummy;
-            ListNode fast = dummy;
+            ListNode pre = new ListNode(-1);
+            pre.next = head;
+            ListNode slow = pre;
+            ListNode fast = pre;
             while (fast.next != null) {
                 if (n <= 0) {
                     slow = slow.next;
@@ -89,7 +89,7 @@ public ListNode removeNthFromEnd(ListNode head, int n) {
             if (slow.next != null) {
                 slow.next = slow.next.next;
             }
-            return dummy.next;
+            return pre.next;
         }
     }
 }

Original file line number	Diff line number	Diff line change
`@@ -75,10 +75,10 @@ public ListNode removeNthFromEnd(ListNode head, int n) {`
`75`	`75`	`public static class Solution3 {`
`76`	`76`	`//a more concise version using the same idea`
`77`	`77`	`public ListNode removeNthFromEnd(ListNode head, int n) {`
`78`		`- ListNode dummy = new ListNode(-1);`
`79`		`- dummy.next = head;`
`80`		`- ListNode slow = dummy;`
`81`		`- ListNode fast = dummy;`
	`78`	`+ ListNode pre = new ListNode(-1);`
	`79`	`+ pre.next = head;`
	`80`	`+ ListNode slow = pre;`
	`81`	`+ ListNode fast = pre;`
`82`	`82`	`while (fast.next != null) {`
`83`	`83`	`if (n <= 0) {`
`84`	`84`	`slow = slow.next;`
`@@ -89,7 +89,7 @@ public ListNode removeNthFromEnd(ListNode head, int n) {`
`89`	`89`	`if (slow.next != null) {`
`90`	`90`	`slow.next = slow.next.next;`
`91`	`91`	`}`
`92`		`- return dummy.next;`
	`92`	`+ return pre.next;`
`93`	`93`	`}`
`94`	`94`	`}`
`95`	`95`	`}`