【LeetCode】Insertion Sort List

#include
#include
using namespace std;

/*
调试记录
bug1：if(head->next == NULL)//第一次这里写成的 = 粗心呀！
bug2：

*/
struct ListNode {
int val;
ListNode *next;
ListNode(int x) : val(x), next(NULL) {}
};

/*
调试用
*/
void printList(ListNode *head,char *name)
{
if(head == NULL)
return;
printf("%10s list:",name);
while(head != NULL)
{
printf("%3d",head->val);
head = head->next;
}
printf("\n");
}
class Solution {
public:
ListNode *insertionSortList(ListNode *head) {
if(head == NULL)
return NULL;
if(head->next == NULL)//第一次这里写成的 = 粗心呀！
return head;
//此时 链表里至少两个结点

ListNode *tmphead = NULL,*p = NULL;
//把head第一个结点取下放到tmphead里
tmphead = head;//到这里 head中至少有一个结点
head = head->next;
tmphead->next= NULL;
while(head != NULL)
{
//把head结点取下来
p = head;
head = head->next;
p->next= NULL;
ListNode *cur = tmphead, *precur = tmphead;

while(cur != NULL)
{
if(p->val <= cur->val)//p放到cur前面 ,也就是 tmphead的后面
{
if(cur == tmphead) //cur是第一个点
{
p->next = cur;
tmphead = p;
cur = tmphead;
precur = tmphead;
break;
}
else
{
p->next = cur;
precur->next = p;
break;
}
}
precur = cur;
cur = cur->next;
}
if(cur == NULL)//如果遍历了整个链表，那个新结点应该放到链表最后
{
precur->next = p;
p->next = NULL;
}
}//enc of while(head != NULL)
return tmphead;
}
};
/*
创建一个链表
*/
ListNode *listCreate(vector &listnode, int input[],int n)
{
if(n < 1)
return NULL;
for(int i = 0;inext = &listnode[i];
p = &listnode[i];
}
p = &listnode[0];
return p;
}
void checkList(ListNode *head,int n)
{
int ret = 1;
if(head == NULL)
{
if(n != 0) cout<<"----------------failed"<next;
printf("list:%3d",prep->val);
int i = 1;
while(p != NULL)
{
if(prep->val > p->val)
{
ret = 0;
}
prep = p;
p = p->next;
i++;
printf("%3d",prep->val);
}
if(i == n && ret == 1)	cout<<"-----------passed"< listnode;//最多含100个数据
int test[10] = {0,1,2,3,4,5,6,7,8,9};//正序
ListNode *temp = listCreate(listnode,test,10);
Solution so;
printList(temp,"处理前");
temp = so.insertionSortList(temp);
checkList(temp,10);
listnode.clear();
}
void test2()
{
vector listnode;//最多含100个数据
int test[10] = {9,8,7,6,5,4,3,2,1,0};//逆序
ListNode *temp = listCreate(listnode,test,10);
Solution so;
//printList(temp,"处理前");
temp = so.insertionSortList(temp);
checkList(temp,10);
listnode.clear();
}
void test3()
{
vector listnode;//最多含100个数据
int test[200] = {9,8,7,6,5,48,3,2,1,0,48,12,25,86,41,47,32,58,69,1,20,45,6};//随机带重复
ListNode *temp = listCreate(listnode,test,20);
//printList(temp,"no sort");
Solution so;
temp = so.insertionSortList(temp);
checkList(temp,20);
listnode.clear();
}
int main()
{
//我个人喜欢使用日志的形式查看输出
freopen("log.txt","w",stdout) ;
test1();
test2();

test3();
freopen("CON","w",stdout) ;
system("log.txt");
}