You are given two linked lists representing two non-negative numbers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the two numbers and return it as a linked list.
Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)
Output: 7 -> 0 -> 8
题目简单,没什么值得优化的
AC代码:
/**
* Definition for singly-linked list.
* struct ListNode {
* int val;
* ListNode *next;
* ListNode(int x) : val(x), next(NULL) {}
* };
*/
class Solution {
public:
ListNode *addTwoNumbers(ListNode *l1, ListNode *l2) {
ListNode*result=NULL;
ListNode*lt1=l1;
ListNode*lt2=l2;
ListNode*tmp,*curr;
int carry=0;
int num;
result=(ListNode*)malloc(sizeof(ListNode));
result->next=NULL;
//result->val=9999;
curr=result;
while(lt1!=NULL&<2!=NULL){
if((num=lt1->val+lt2->val+carry)>9){
carry=1;
num%=10;
}else{
carry=0;
}
tmp=(ListNode*)malloc(sizeof(ListNode));
tmp->val=num;
tmp->next=NULL;
curr->next=tmp;
curr=tmp;
lt1=lt1->next;
lt2=lt2->next;
}
if(lt1!=NULL){
while(lt1!=NULL){
if((num=lt1->val+carry)>9){
carry=1;
num%=10;
}else{
carry=0;
}
tmp=(ListNode*)malloc(sizeof(ListNode));
tmp->val=num;
tmp->next=NULL;
curr->next=tmp;
curr=tmp;
lt1=lt1->next;
}
}
if(lt2!=NULL){
while(lt2!=NULL){
if((num=lt2->val+carry)>9){
carry=1;
num%=10;
}else{
carry=0;
}
tmp=(ListNode*)malloc(sizeof(ListNode));
tmp->val=num;
tmp->next=NULL;
curr->next=tmp;
curr=tmp;
lt2=lt2->next;
}
}
if(carry==1){
tmp=(ListNode*)malloc(sizeof(ListNode));
tmp->val=1;
tmp->next=NULL;
curr->next=tmp;
curr=tmp;
}
return result->next;
}
};