LeetCode - 2. Add Two Numbers
2. Add Two Numbers
Problem's Link
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Mean:
给你两个数字链表,让你将两个链表相加,结果保存在一个新链表中.
analyse:
最基本的链表操作.
做链表题时只需注意:先分配(new ListNode(val)),再h=h->next.也就是不要将指针指向空指针.
Time complexity: O(N)
view code
/**
* -----------------------------------------------------------------
* Copyright (c) 2016 crazyacking.All rights reserved.
* -----------------------------------------------------------------
* Author: crazyacking
* Date : 2016-01-29-16.16
*/
#include <queue>
#include <cstdio>
#include <set>
#include <string>
#include <stack>
#include <cmath>
#include <climits>
#include <map>
#include <cstdlib>
#include <iostream>
#include <vector>
#include <algorithm>
#include <cstring>
using namespace std;
typedef long long(LL);
typedef unsigned long long(ULL);
const double eps(1e-8);
// 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)
{
int jinwei=0;
ListNode *h1=l1;
ListNode *h2=l2;
ListNode *ans,*ret;
bool isFirst=true;
while(h1&&h2)
{
int val=h1->val+h2->val+jinwei;
int now=val%10;
jinwei=val/10;
if(isFirst)
{
ans=new ListNode(now);
ret=ans;
isFirst=false;
}
else
{
ans->next=new ListNode(now);
ans=ans->next;
}
h1=h1->next;
h2=h2->next;
}
while(h1)
{
int val=h1->val+jinwei;
int now=val%10;
jinwei=val/10;
if(isFirst)
{
ans=new ListNode(now);
ret=ans;
isFirst=false;
}
else
{
ans->next=new ListNode(now);
ans=ans->next;
}
h1=h1->next;
}
while(h2)
{
int val=h2->val+jinwei;
int now=val%10;
jinwei=val/10;
if(isFirst)
{
ans=new ListNode(now);
ret=ans;
isFirst=false;
}
else
{
ans->next=new ListNode(now);
ans=ans->next;
}
h2=h2->next;
}
while(jinwei)
{
ans->next=new ListNode(jinwei%10);
jinwei/=10;
ans=ans->next;
}
return ret;
}
};
int main()
{
int n1,n2;
while(cin>>n1>>n2)
{
ListNode *h1,*head1;
ListNode *h2,*head2;
int tmp;
for(int i=0; i<n1; ++i)
{
cin>>tmp;
if(!i)
{
h1=new ListNode(tmp);
head1=h1;
}
else
{
h1->next=new ListNode(tmp);
h1=h1->next;
}
}
for(int i=0; i<n2; ++i)
{
cin>>tmp;
if(!i)
{
h2=new ListNode(tmp);
head2=h2;
}
else
{
h2->next=new ListNode(tmp);
h2=h2->next;
}
}
Solution solution;
ListNode* ans=solution.addTwoNumbers(head1,head2);
puts("----------------------");
while(ans)
{
cout<<ans->val;
ans=ans->next;
}
cout<<endl;
}
return 0;
}
* -----------------------------------------------------------------
* Copyright (c) 2016 crazyacking.All rights reserved.
* -----------------------------------------------------------------
* Author: crazyacking
* Date : 2016-01-29-16.16
*/
#include <queue>
#include <cstdio>
#include <set>
#include <string>
#include <stack>
#include <cmath>
#include <climits>
#include <map>
#include <cstdlib>
#include <iostream>
#include <vector>
#include <algorithm>
#include <cstring>
using namespace std;
typedef long long(LL);
typedef unsigned long long(ULL);
const double eps(1e-8);
// 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)
{
int jinwei=0;
ListNode *h1=l1;
ListNode *h2=l2;
ListNode *ans,*ret;
bool isFirst=true;
while(h1&&h2)
{
int val=h1->val+h2->val+jinwei;
int now=val%10;
jinwei=val/10;
if(isFirst)
{
ans=new ListNode(now);
ret=ans;
isFirst=false;
}
else
{
ans->next=new ListNode(now);
ans=ans->next;
}
h1=h1->next;
h2=h2->next;
}
while(h1)
{
int val=h1->val+jinwei;
int now=val%10;
jinwei=val/10;
if(isFirst)
{
ans=new ListNode(now);
ret=ans;
isFirst=false;
}
else
{
ans->next=new ListNode(now);
ans=ans->next;
}
h1=h1->next;
}
while(h2)
{
int val=h2->val+jinwei;
int now=val%10;
jinwei=val/10;
if(isFirst)
{
ans=new ListNode(now);
ret=ans;
isFirst=false;
}
else
{
ans->next=new ListNode(now);
ans=ans->next;
}
h2=h2->next;
}
while(jinwei)
{
ans->next=new ListNode(jinwei%10);
jinwei/=10;
ans=ans->next;
}
return ret;
}
};
int main()
{
int n1,n2;
while(cin>>n1>>n2)
{
ListNode *h1,*head1;
ListNode *h2,*head2;
int tmp;
for(int i=0; i<n1; ++i)
{
cin>>tmp;
if(!i)
{
h1=new ListNode(tmp);
head1=h1;
}
else
{
h1->next=new ListNode(tmp);
h1=h1->next;
}
}
for(int i=0; i<n2; ++i)
{
cin>>tmp;
if(!i)
{
h2=new ListNode(tmp);
head2=h2;
}
else
{
h2->next=new ListNode(tmp);
h2=h2->next;
}
}
Solution solution;
ListNode* ans=solution.addTwoNumbers(head1,head2);
puts("----------------------");
while(ans)
{
cout<<ans->val;
ans=ans->next;
}
cout<<endl;
}
return 0;
}