leetcode 2. 两数相加
2020-10-19 本文已影响0人
Source_Chang
链表结构：
C++：
struct ListNode {
public:
int val;
ListNode *next;
ListNode() : val(0), next(nullptr) {}
ListNode(int x) : val(x), next(nullptr) {}
ListNode(int x, ListNode *next) : val(x), next(next) {}
};
C++：
class Solution {
public:
ListNode* addTwoNumbers(ListNode* l1, ListNode* l2) {
ListNode *head = NULL;
ListNode *node = NULL;
int offset = 0;
while ( l1 || l2 ) {
int left = 0;
if ( l1 ) {
left = l1 -> val;
l1 = l1 -> next;
}
int right = 0;
if ( l2 ) {
right = l2 -> val;
l2 = l2 -> next;
}
int sum = left + right + offset;
offset = sum / 10;
int rest = sum % 10;
if ( node ) {
if ( node -> next ) {
node -> next -> val = rest;
} else {
node -> next = new ListNode(rest);
}
node = node -> next;
} else {
node = new ListNode(rest);
}
if ( !head ) {
head = node;
}
}
if ( offset != 0 ) {
if ( node ) {
if ( node -> next ) {
node -> next -> val = offset;
} else {
node -> next = new ListNode(offset);
}
node = node -> next;
}
}
if ( node ) {
node -> next = NULL;
}
return head;
}
};
