标签：des style blog class code c
Given a sorted linked list, delete all duplicates such that each element appear only once.
For example,
Given 1->1->2, return 1->2.
Given
1->1->2->3->3, return 1->2->3.
如果下一个节点和当前节点的值一样，就继续往后。这样找到的是重复数的最后一个。比如1->1->2;
当然也可以找到重复数的第一个数；
注意delete掉那些重复的点。
1 class Solution { 2 public: 3 ListNode *deleteDuplicates(ListNode *head) { 4 ListNode *p = head, *newH = NULL, *tail, *tmp; 5 while (p != NULL) { 6 while (p->next != NULL && p->next->val == p->val) { 7 tmp = p->next; 8 delete p; 9 p = tmp; 10 } 11 if (newH == NULL) { 12 newH = p; 13 } else { 14 tail->next = p; 15 } 16 tail = p; 17 p = p->next; 18 } 19 return newH; 20 } 21 };
Given a sorted linked list, delete all nodes that have duplicate numbers, leaving only distinct numbers from the original list.
For example,
Given 1->2->3->3->4->4->5, return
1->2->5.
Given 1->1->1->2->3, return 2->3.
和Remove Duplicates from Sorted List I类似。加了一个判断是否重复数的条件。最后tail要指向NULL，因为原链表最后一个元素不一定会加进来。
这道题用c++很奇怪。下面的代码没有delete是可以accepted的。
1 class Solution { 2 public: 3 ListNode *deleteDuplicates(ListNode *head) { 4 ListNode *p = head, *newH = NULL, *tail, *current, *tmp; 5 while (p != NULL) { 6 current = p; 7 while (p->next != NULL && p->next->val == p->val) p = p->next; 8 if (p == current) { 9 if (newH == NULL) { 10 newH = p; 11 } else { 12 tail->next = p; 13 } 14 tail = p; 15 } 16 p = p->next; 17 } 18 if (tail) tail->next = NULL; 19 return newH; 20 } 21 };
但是加了delete的逻辑之后就runtime error了。这份代码应该是没有问题的。难道是leetcode自己有问题？
1 class Solution { 2 public: 3 ListNode *deleteDuplicates(ListNode *head) { 4 ListNode *p = head, *newH = NULL, *tail, *current, *tmp; 5 while (p != NULL) { 6 current = p; 7 while (p->next != NULL && p->next->val == p->val) { 8 tmp = p->next; 9 delete p; 10 p = tmp; 11 } 12 tmp = p->next; 13 if (p == current) { 14 if (newH == NULL) { 15 newH = p; 16 } else { 17 tail->next = p; 18 } 19 tail = p; 20 } else { 21 delete p; 22 } 23 p = tmp; 24 } 25 if (tail) tail->next = NULL; 26 return newH; 27 } 28 };
Leetcode | Remove Duplicates from Sorted List I && II,布布扣,bubuko.com
Leetcode | Remove Duplicates from Sorted List I && II
标签：des style blog class code c
原文地址：http://www.cnblogs.com/linyx/p/3734084.html
