剑指 Offer II 025. 链表中的两数相加

剑指 Offer II 025. 链表中的两数相加

class Solution {
    
public:
    ListNode* addTwoNumbers(ListNode* l1, ListNode* l2) {
    
		stack<int>s1,s2;
		while(l1){
    
			s1.push(l1->val);
			l1=l1->next;
		}
		while(l2){
    
			s2.push(l2->val);
			l2=l2->next;
		}
		int carry=0;
		ListNode*res=nullptr;
		while(!s1.empty() or !s2.empty() or carry!=0){
    
			int a=s1.empty()?0:s1.top();
			int b=s2.empty()?0:s2.top();
			if(!s1.empty()) s1.pop();
			if(!s2.empty()) s2.pop();
			int cur=a+b+carry;
			carry=cur/10;
			cur%=10;
			ListNode*curnode=new ListNode(cur);
			curnode->next=res;
			res=curnode;
		}
		return res;
    }
};

class Solution:
    def addTwoNumbers(self, l1: ListNode, l2: ListNode) -> ListNode:
        s1, s2 = [], []
        while l1:
            s1.append(l1.val)
            l1 = l1.next
        while l2:
            s2.append(l2.val)
            l2 = l2.next
        ans = None
        carry = 0
        while s1 or s2 or carry != 0:
            a = 0 if not s1 else s1.pop()
            b = 0 if not s2 else s2.pop()
            cur = a + b + carry
            carry = cur // 10
            cur %= 10
            curnode = ListNode(cur)
            curnode.next = ans
            ans = curnode
        return ans