21. Merge Two Sorted Lists
Problem's Link
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Mean:
将两个非递减排列的链表合并成一个链表,所得链表依然按照非递减顺序排列.
analyse:
链表的基本操作.
Time complexity: O(N)
view code
/**
* -----------------------------------------------------------------
* Copyright (c) 2016 crazyacking.All rights headerved.
* -----------------------------------------------------------------
* Author: crazyacking
* Date : 2016-02-17-16.50
*/
#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 * mergeTwoLists( ListNode * l1 , ListNode * l2)
{
ListNode * res = NULL , * head = NULL;
bool isFirst = true;
while( l1 && l2)
{
if( l1 -> val < l2 -> val)
{
if( isFirst)
{
head = new ListNode( l1 -> val);
res = head;
isFirst = false;
}
else
{
head -> next = new ListNode( l1 -> val);
head = head -> next;
}
l1 = l1 -> next;
}
else
{
if( isFirst)
{
head = new ListNode( l2 -> val);
res = head;
isFirst = false;
}
else
{
head -> next = new ListNode( l2 -> val);
head = head -> next;
}
l2 = l2 -> next;
}
}
while( l1)
{
if( isFirst)
{
head = new ListNode( l1 -> val);
res = head;
isFirst = false;
}
else
{
head -> next = new ListNode( l1 -> val);
head = head -> next;
}
l1 = l1 -> next;
}
while( l2)
{
if( isFirst)
{
head = new ListNode( l2 -> val);
res = head;
isFirst = false;
}
else
{
head -> next = new ListNode( l2 -> val);
head = head -> next;
}
l2 = l2 -> next;
}
return res;
}
};
int main()
{
return 0;
}
/*
*/
* -----------------------------------------------------------------
* Copyright (c) 2016 crazyacking.All rights headerved.
* -----------------------------------------------------------------
* Author: crazyacking
* Date : 2016-02-17-16.50
*/
#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 * mergeTwoLists( ListNode * l1 , ListNode * l2)
{
ListNode * res = NULL , * head = NULL;
bool isFirst = true;
while( l1 && l2)
{
if( l1 -> val < l2 -> val)
{
if( isFirst)
{
head = new ListNode( l1 -> val);
res = head;
isFirst = false;
}
else
{
head -> next = new ListNode( l1 -> val);
head = head -> next;
}
l1 = l1 -> next;
}
else
{
if( isFirst)
{
head = new ListNode( l2 -> val);
res = head;
isFirst = false;
}
else
{
head -> next = new ListNode( l2 -> val);
head = head -> next;
}
l2 = l2 -> next;
}
}
while( l1)
{
if( isFirst)
{
head = new ListNode( l1 -> val);
res = head;
isFirst = false;
}
else
{
head -> next = new ListNode( l1 -> val);
head = head -> next;
}
l1 = l1 -> next;
}
while( l2)
{
if( isFirst)
{
head = new ListNode( l2 -> val);
res = head;
isFirst = false;
}
else
{
head -> next = new ListNode( l2 -> val);
head = head -> next;
}
l2 = l2 -> next;
}
return res;
}
};
int main()
{
return 0;
}
/*
*/