Deque C语言实现 && C++ STL基本操作

Deque

deque (usually pronounced like "deck") is an irregular acronym ofdouble-endedqueue. Double-ended queues are sequence containers with dynamic sizes that can be expanded or contracted on both ends (either its front or its back).

内部实现   example：

A "deque" is a data structure consisting of a list of items, on which the following operations are possible:

• Push(X,D): Insert item X on the front end of deque D.
• Pop(D): Remove the front item from deque D and return it.
• Inject(X,D): Insert item X on the rear end of deque D.
• Eject(D): Remove the rear item from deque D and return it.Write routines to support the deque that take O(1) time per operation.

Format of functions:

Deque CreateDeque();int Push( ElementType X, Deque D );ElementType Pop( Deque D );int Inject( ElementType X, Deque D );ElementType Eject( Deque D );

where Deque is defined as the following:

typedef struct Node *PtrToNode;struct Node {    ElementType Element;    PtrToNode Next, Last;};typedef struct DequeRecord *Deque;struct DequeRecord {    PtrToNode Front, Rear;};

Here the deque is implemented by a doubly linked list with a header. Front andRear point to the two ends of the deque respectively.Front always points to the header. The deque is empty whenFront andRear both point to the same dummy header.Note:Push and Inject are supposed to return 1 if the operations can be done successfully, or 0 if fail. If the deque is empty,Pop andEject must returnERROR which is defined by the judge program.

Sample program of judge:

#include <stdio.h>#include <stdlib.h>#define ElementType int#define ERROR 1e5typedef enum { push, pop, inject, eject, end } Operation;typedef struct Node *PtrToNode;struct Node {    ElementType Element;    PtrToNode Next, Last;};typedef struct DequeRecord *Deque;struct DequeRecord {    PtrToNode Front, Rear;};Deque CreateDeque();int Push( ElementType X, Deque D );ElementType Pop( Deque D );int Inject( ElementType X, Deque D );ElementType Eject( Deque D );Operation GetOp();          /* details omitted */void PrintDeque( Deque D ); /* details omitted */int main(){    ElementType X;    Deque D;    int done = 0;    D = CreateDeque();    while (!done) {        switch(GetOp()) {        case push:             scanf("%d", &X);            if (!Push(X, D)) printf("Memory is Full!\n");            break;        case pop:            X = Pop(D);            if ( X==ERROR ) printf("Deque is Empty!\n");            break;        case inject:             scanf("%d", &X);            if (!Inject(X, D)) printf("Memory is Full!\n");            break;        case eject:            X = Eject(D);            if ( X==ERROR ) printf("Deque is Empty!\n");            break;        case end:            PrintDeque(D);            done = 1;            break;        }    }    return 0;}/* Your function will be put here */

Sample Input:

PopInject 1PopEjectPush 1Push 2EjectInject 3End

Sample Output:

Deque is Empty!Deque is Empty!Inside Deque: 2 3

Deque CreateDeque(){    PtrToNode Temp_Node = (PtrToNode)malloc(sizeof(struct Node));   //创建节点    Deque Temp_Record = (Deque)malloc(sizeof(struct DequeRecord));  //创建队列    Temp_Node->Next = Temp_Node->Last = NULL;    Temp_Record->Front = Temp_Record->Rear = Temp_Node;    return Temp_Record; //返回队列首地址}int Push( ElementType X, Deque D ){    //Insert element at beginning     PtrToNode Tnode = (PtrToNode)malloc(sizeof(struct Node));    if(!Tnode)        return 0;    //插入    Tnode->Element = X;    Tnode->Last = D->Front;    Tnode->Next = D->Front->Next;    if(D->Front->Next)  //Front原来所指的节点的前一个（Last）节点指向新的节点        D->Front->Next->Last = Tnode;    D->Front->Next = Tnode; //Front的下一个指向新节点    //空队列    if(D->Front == D->Rear)        D->Rear = Tnode;//更新Rear节点    return 1;}ElementType Pop( Deque D ){    //Delete first element    if(D->Front == D->Rear) //队列为空        return ERROR;    PtrToNode Tnode = D->Front->Next;    //若pop之后为空队列，则Rear指向Front    if(D->Front->Next == D->Rear)        D->Rear = D->Front;    //Front指向队列的第二个元素    D->Front->Next = D->Front->Next->Next;    ElementType temp;    temp = Tnode->Element;    free(Tnode);    return temp;}int Inject( ElementType X, Deque D ){    //Add element at the end     PtrToNode Tnode = (PtrToNode)malloc(sizeof(struct Node));   //创建节点    if(!Tnode)        return ERROR;    //插入    Tnode->Element = X;    Tnode->Next = NULL;    D->Rear->Next = Tnode;    Tnode->Last = D->Rear;        if(D->Rear == D->Front)        D->Front->Next = Tnode;    D->Rear = Tnode;//更新Rear    return 1;}ElementType Eject( Deque D ){    //Delete last element    if(D->Front == D->Rear)        return ERROR;    PtrToNode Tnode = D->Rear;    ElementType temp = D->Rear->Element;    D->Rear = D->Rear->Last;    free(Tnode);    return temp;}

STL deque成员函数：

Member functions

(constructor)    Construct deque container 

(destructor)    Deque destructor

operator=    Assign content 

Iterators:

begin    Return iterator to beginning 

end    Return iterator to end

rbegin    Return reverse iterator to reverse beginning 

rend    Return reverse iterator to reverse end 

cbegin    Return const_iterator to beginning

cend    Return const_iterator to end

crbegin    Return const_reverse_iterator to reverse beginning

crend    Return const_reverse_iterator to reverse end

Capacity:

size    Return size 

max_size    Return maximum size 

resize    Change size

empty    Test whether container is empty

shrink_to_fit    Shrink to fit

Element access:

operator[]    Access element 

at    Access element 

front    Access first element

back    Access last element

Modifiers:

assign    Assign container content 

push_back    Add element at the end

push_front    Insert element at beginning

pop_back    Delete last element

pop_front    Delete first element

insert    Insert elements

erase    Erase elements

swap    Swap content 

clear    Clear content

emplace    Construct and insert element 

emplace_front    Construct and insert element at beginning

emplace_back    Construct and insert element at the end

Allocator:

get_allocator    Get allocator

常用方法 example：

#include <deque>#include <cstdio>#include <algorithm>using namespace std;int main(){deque<int> q(20); //创建dequedeque<int>::iterator pos;   //创建构造器int i;    for (i = 0; i < 20; ++i)    q[i] = i;//输出dequeprintf("输出deque中数据:\n");for (i = 0; i < 20; ++i)printf("%d ", q[i]);putchar('\n');//在头尾加入新数据q.push_back(100);q.push_front(i);//输出dequeprintf("\n输出deque中数据:\n");for (pos = q.begin(); pos != q.end(); pos++)printf("%d ", *pos);putchar('\n');//查找printf("\n查找%d\n", 18);pos = find(q.begin(), q.end(), 18);if (pos != q.end())printf("find %d success\n", *pos);elseprintf("find failed\n");//在头尾删除数据q.pop_back();q.pop_front();//输出dequeprintf("\n输出deque中数据:\n");for (pos = q.begin(); pos != q.end(); pos++)printf("%d ", *pos);putchar('\n');return 0;}