数据结构与算法——线性表—双向链表操作（含代码）

注意：这里的头指针是不包含数据的

双向链表（double linked list）的结点中有两个指针域，一个指向“直接后继”，另一个指向“直接前驱”。
typedef struct DLNode{
ElemType data;
DLNode *prior;
DLNode *next;
}DLNode,*DuLinkList;

#include “DList.h”

#pragma once
#include <iostream>
using namespace std;

typedef int ElemType ;

typedef struct DLNode
{
	ElemType data;
	DLNode *prior;
	DLNode *next;

}DLNode;

void destoryDList(DLNode* &pHead)
{
	if (pHead == NULL)
	{
		return;
	}

	DLNode *p = pHead;
	while (p)
	{
		p = p->next;
		free(pHead);
		if (p != NULL)
			p->prior = NULL;
		pHead = p;
	}
}

void initDList(DLNode* & pHead)//创建一个新头
{
	if (pHead != NULL)
	{
		destoryDList(pHead);
	}

	DLNode *p = (DLNode*)malloc(sizeof(DLNode));
	p->prior = NULL;
	p->data = 0;
	p->next = NULL;

	pHead = p;
	
}

void creatDList(DLNode* & pHead,ElemType* a,int len)//创建双链表
{
	if (pHead == NULL)
	{
		return;//zanshi 
	}

	DLNode *p = pHead;
	DLNode *q = NULL;

	for (int i = 0; i < len; ++i)
	{
		//创建一个结点
		q = (DLNode*)malloc(sizeof(DLNode));
		q->prior = NULL;
		q->data = a[i];
		q->next = NULL;

		//连接
		p->next = q;
		q->prior = p;

		//为下次准备
		p = q;
		q = NULL;

	}
	
}
void myPrintDList(const DLNode* pHead)
{
	if (pHead == NULL || pHead->next == NULL)
	{
		cout << "the DList is empty " << endl;
		return;
	}

	DLNode* p = pHead->next;

	cout << "the DList is: ";
	while (p)
	{
		cout << p->data << " ";
		p = p->next;
	}

	cout << endl;

}


void myReservePrintDList(DLNode* pHead)
{
	if (pHead == NULL || pHead->next == NULL)
	{
		cout << "the DList is empty " << endl;
		return;
	}

	DLNode* p = pHead;

	
	while (p->next != NULL)
	{
		p = p->next;
	}

	cout << "the RDList is: ";
	while (p != pHead)
	{
		cout << p->data << " ";
		p = p->prior;
	}
	cout << endl;

}



int getLengDList(DLNode* pHead)
{
	if (pHead == NULL)
	{
		return 0;
	}

	DLNode* p = pHead->next;
	int len = 0;

	while (p)
	{
		++len;
		p = p->next;
		
	}

	return len;
}

void insertDList(DLNode* &pHead, int pos, ElemType val)
{
	if (pHead == NULL || pos < 0 || pos > getLengDList(pHead))
	{
		return;
	}

	//找到要插入的位置
	DLNode* p = pHead;
	while (pos > 0)
	{
		p = p->next;
		--pos;
	}

	//创建结点
	DLNode * q = (DLNode*)malloc(sizeof(DLNode));
	q->prior = NULL;
	q->data = val;
	q->next = NULL;

	//连接
	q->next = p->next;//顺序很重要，一旦移动有可能后继前驱都会变
	if (p->next != NULL)//不为尾元素
	{
		p->next->prior = q;
	}
	p->next = q;
	q->prior = p;

	p = NULL;
	q = NULL;
}

void removeDList(DLNode* &pHead, int pos, ElemType& reRal)
{
	if (pHead == NULL || pHead->next == NULL || pos < 0 || pos >= getLengDList(pHead))
	{
		return;
	}

	//找到要插入的位置
	DLNode *p = pHead;

	while (pos > 0)
	{
		p = p->next;
		--pos;
	}

	DLNode *q = p->next;
	p->next = q->next;
	if(q->next != NULL)//不为尾元素
	{
		q->next->prior = p;
	}
	
	reRal = q->data;
	q->next = NULL;
	q->prior = NULL;
	free(q);


}

test.cpp

#pragma once
#include <iostream>
#include "DList.h"
using namespace std;
#include <vector>

//创建销毁
void test0()
{
	ElemType arr[5] = {0,1,2,3,4};
	DLNode * head = NULL;

	initDList(head);
	myPrintDList(head);
	creatDList(head,arr,sizeof(arr)/sizeof(arr[0]));
	cout << "leng: " << getLengDList(head) << endl;
	myPrintDList(head);
	myReservePrintDList(head);
	destoryDList(head);
	cout << "leng: " << getLengDList(head) << endl;
	myPrintDList(head);	
}

void test1()
{
	ElemType arr[5] = { 0,1,2,3,4 };
	DLNode * head = NULL;

	initDList(head);
	myPrintDList(head);
	creatDList(head, arr, sizeof(arr) / sizeof(arr[0]));
	myPrintDList(head);
	insertDList(head,5,5);
	myPrintDList(head);
	myReservePrintDList(head);

	int removeVal;
	removeDList(head, 5, removeVal);
	myPrintDList(head);
	myReservePrintDList(head);
	cout << "removeVal: " << removeVal << endl;
}

bool Find(int target, vector<vector<int> > array) {

	if (array.empty())
	{
		return false;
	}
	int row = 0;//判断行数
	int col = array[0].size() - 1;
	while (row < array.size() && col >= 0)
	{
		//总列数不等于总行数
		//先判断目标值是否比该行最大值 小
		if (target < array[row][col])//如果小就在本行查找
		{
			--col;
		}
		else if (target > array[row][col])
		{
			++row;
		}
		else//(target == array[row][col])
		{
			return true;
		}
	}
	return false;
}

int main(void)
{
	vector<vector<int>> veci= { {1,2,3,4},{ 2,3,4,5 } };
	cout << veci.size() << " " << veci[0].size() << endl;
	cout << veci[0][0] << " "<< veci[veci.size() - 1][veci[0].size() - 1] << endl;

	cout << Find(6, veci) << endl;
}