链表的归并排序

[xiaolomg]

下午无聊做了个链表的归并排序，代码测试有问题，但找了半天没看出来，哪位大神给看看？

#include <string>
#include <vector>
#include <stack>
#include <iostream>
#include <stdio.h>
#include <stdlib.h>

using namespace std;

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

void print(ListNode* node){
	while (node){
		printf("%d ", node->val);
		node = node->next;
	}
	printf("\n");
}

class Solution {
public:
    ListNode *sortList(ListNode *head) {
        if (!head){
        	return  NULL;
        }
        
        if (!head->next){
        	return head;
        }
        
        ListNode* after = devide(head);
        
        print(head);
        print(after);
        
        ListNode* res1 = sortList(head);
        ListNode* res2 = sortList(after);
        
        return merge(res1, res2);
    }
    
    ListNode * devide(ListNode *head){
    	ListNode* slow = head;
    	ListNode* quick = head;
    	
    	while (quick){
    		quick = quick->next;
    		
    		if (quick){
    			quick = quick->next;
    			slow = slow->next;
    		}
    	}
    	
    	ListNode* res = slow->next;
    	slow->next = NULL;
    	
    	return res;
    }
    
    ListNode* merge(ListNode *left, ListNode *right){
    	if (!left && !right){
    		return NULL;
    	}  
    	
    	if (left && !right){
    		return left;
    	}
    	
    	if (!left && right){
    		return right;
    	}
    	
    	ListNode* resHead = NULL;
    	ListNode* res = NULL;
    	while (left && right){
    		ListNode* tmp = NULL;
    		if (left->val < right->val){
    			tmp = left;
    			left = left->next;
    		}
    		else{
    			tmp = right;
    			right = right->next;
    		}
    		
    		if (!res){
    			resHead = tmp;
    			res = tmp;
    		}
    		else{
    			res->next = tmp;
    			res = res->next;
    		}
    	}
    	
    	if (left){
			res->next = left;
    	}
    	
    	if (right){
    		res->next = right;
    	}
    	
    	return resHead;
    }
};

void insert(ListNode*& node, int val){
	ListNode* newNode = new ListNode(val);
	ListNode* tmpNode = node;
	if (!node){
		node = newNode;
	}
	else{
		while (tmpNode->next){
			tmpNode = tmpNode->next;
		}
		
		tmpNode->next = newNode;
	}
}


int main(){
	ListNode* head = NULL;
	insert(head, 2);
	insert(head, 1);
	insert(head, 3);
	//print(head);
	Solution s;
	s.sortList(head);
	//print(head);
}

[bobo928843007]

insert(ListNode* & node, int val)

报错什么意思，要改成下面的吗

insert(ListNode*  node, int val)

[logiciel]

#include <string>
#include <vector>
#include <stack>
#include <iostream>
#include <stdio.h>
#include <stdlib.h>

using namespace std;

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

void print(ListNode* node){
  while (node){
    printf("%d ", node->val);
    node = node->next;
  }
  printf("\n");
}

class Solution {
public:
  ListNode *sortList(ListNode *head) {
    if (!head){
      return  NULL;
    }

    if (!head->next){
      return head;
    }

    ListNode* after = devide(head);

    print(head);
    print(after);

    ListNode* res1 = sortList(head);
    ListNode* res2 = sortList(after);

    return merge(res1, res2);
  }

  ListNode * devide(ListNode *head){
    ListNode* slow = head;
    ListNode* quick = head;

    while (quick){
      quick = quick->next;

      if (quick){
        quick = quick->next;
        slow = slow->next;
      }
    }

    ListNode* res = slow->next;
    if (NULL == res)     //加 处理只有2个节点的情况
    {                    //加
      res = slow;        //加
      head->next = NULL; //加
    }                    //加
    else                 //加
    {
      slow->next = NULL;
    }

    return res;
  }

  ListNode* merge(ListNode *left, ListNode *right){
    if (!left && !right){
      return NULL;
    }  

    if (left && !right){
      return left;
    }

    if (!left && right){
      return right;
    }

    ListNode* resHead = NULL;
    ListNode* res = NULL;
    while (left && right){
      ListNode* tmp = NULL;
      if (left->val < right->val){
        tmp = left;
        left = left->next;
      }
      else{
        tmp = right;
        right = right->next;
      }

      if (!res){
        resHead = tmp;
        res = tmp;
      }
      else{
        res->next = tmp;
        res = res->next;
      }
    }

    if (left){
      res->next = left;
    }

    if (right){
      res->next = right;
    }

    return resHead;
  }
};

void insert(ListNode*& node, int val){
  ListNode* newNode = new ListNode(val);
  ListNode* tmpNode = node;
  newNode->next = NULL;//加
  if (!node){
    node = newNode;
  }
  else{
    while (tmpNode->next){
      tmpNode = tmpNode->next;
    }

    tmpNode->next = newNode;
  }
}


int main(){
  ListNode* head = NULL;
  insert(head, 2);
  insert(head, 1);
  insert(head, 3);
  print(head);
  Solution s;
  head = s.sortList(head);//改 s.sortList(head);
  print(head);
}