题解 | #JZ25 合并两个排序的链表#
合并两个排序的链表
https://www.nowcoder.com/practice/d8b6b4358f774294a89de2a6ac4d9337
/*
struct ListNode {
int val;
struct ListNode *next;
ListNode(int x) :
val(x), next(NULL) {
}
};*/
class Solution {
public:
// void ListInsert(ListNode** Head, ListNode* insert_node) {
// ListNode* Node = *Head;
// insert_node->next = Node->next;
// Node->next = insert_node;
// *Head = insert_node->next;
// }
void Listpushback(ListNode** Head,int x){
ListNode* Node = new ListNode(x);
if (*Head ==NULL){
*Head = Node;
}
else{
ListNode* p = *Head;
while(p->next!=NULL){
p = p->next;
// cout<<p->val<<'+';
}
p->next = Node;
}
}
ListNode* Merge(ListNode* pHead1, ListNode* pHead2) {
// ListNode* small;
// ListNode* large;
ListNode* result = NULL;
if (pHead1 == NULL) {
return pHead2;
} else if (pHead2 == NULL) {
return pHead1;
} else {
// if (pHead1 -> val <= pHead2 -> val) {
// small = pHead1;
// large = pHead2;
// } else {
// small = pHead2;
// large = pHead1;
// }
// ListNode* temp_p = small;
while (pHead1 != NULL && pHead2 != NULL) {
if(pHead1->val<=pHead2->val){
Listpushback(&result, pHead1->val);
// cout<<pHead1->val<<' ';
pHead1 = pHead1->next;
}
else{
Listpushback(&result, pHead2->val);
// cout<<pHead2->val<<' ';
pHead2 = pHead2->next;
}
}
if(pHead1 ==NULL){
while(pHead2 !=NULL){
Listpushback(&result, pHead2->val);
pHead2 = pHead2->next;
}
}
else{
while(pHead1 !=NULL){
Listpushback(&result, pHead1->val);
pHead1 = pHead1->next;
}
}
return result;
}
}
};
