Commit 53952ae

committed

LC#203 remove given value from linked list,iterative and recursive solution

1 parent 3da6417 commit 53952aeCopy full SHA for 53952ae

File tree

+61

-0

lines changed

+61

-0

lines changed

Lines changed: 61 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,61 @@`
	`1`	`+package LinkedList;`
	`2`	`+`
	`3`	`+public class RemoveLinkedListElement203 {`
	`4`	`+`
	`5`	`+ public class ListNode {`
	`6`	`+ int val;`
	`7`	`+ ListNode next;`
	`8`	`+`
	`9`	`+ ListNode() {`
	`10`	`+ }`
	`11`	`+`
	`12`	`+ ListNode(int val) {`
	`13`	`+ this.val = val;`
	`14`	`+ }`
	`15`	`+`
	`16`	`+ ListNode(int val, ListNode next) {`
	`17`	`+ this.val = val;`
	`18`	`+ this.next = next;`
	`19`	`+ }`
	`20`	`+ }`
	`21`	`+`
	`22`	`+ // O(N) time, O(1) space`
	`23`	`+ public ListNode removeElements(ListNode head, int val) {`
	`24`	`+`
	`25`	`+ if (head == null)`
	`26`	`+ if (head == null)`
	`27`	`+ return null;`
	`28`	`+`
	`29`	`+ ListNode dummy = new ListNode(-1);`
	`30`	`+ dummy.next = head;`
	`31`	`+ ListNode tail = dummy;`
	`32`	`+`
	`33`	`+ while (head != null) {`
	`34`	`+ if (head.val == val) {`
	`35`	`+ ListNode temp = head.next;`
	`36`	`+ tail.next = temp;`
	`37`	`+ head = temp;`
	`38`	`+ } else {`
	`39`	`+ head = head.next;`
	`40`	`+ tail = tail.next;`
	`41`	`+ }`
	`42`	`+ }`
	`43`	`+`
	`44`	`+ return dummy.next;`
	`45`	`+ }`
	`46`	`+`
	`47`	`+ // recursive approach`
	`48`	`+ public ListNode removeElementsRecursive(ListNode head, int val) {`
	`49`	`+`
	`50`	`+ if (head == null)`
	`51`	`+ return null;`
	`52`	`+`
	`53`	`+ head.next = removeElementsRecursive(head.next, val);`
	`54`	`+`
	`55`	`+ // can also write it using ternary operator`
	`56`	`+ if (head.val == val) {`
	`57`	`+ return head.next;`
	`58`	`+ } else`
	`59`	`+ return head;`
	`60`	`+ }`
	`61`	`+}`

Comments

(0)