文章目录

• 一、栈的实现
• 二、队列的实现

一、栈的实现

栈是一种特殊的线性表，只允许在固定的一端进行插入和删除元素的操作，进行数据插入和删除操作的一端称为栈顶，另一端称为栈低。栈遵循数据后进先出的原则。

创建一个栈：

typedef int STDatatype;
typedef struct Stack
{STDatatype* a;int capacity; //容量int top; //栈顶
}ST;

当栈顶初始化为0时，代码如下：

top先放数据，再++

//初始化栈
void StackInit(ST* ps)
{assert(ps);ps->a = (STDatatype*)malloc(sizeof(STDatatype) * 4);if (ps->a == NULL){perror("malloc fail");exit(-1);}ps->top = 0;ps->capacity = 4;
}
//销毁栈
void StackDestroy(ST* ps)
{assert(ps);free(ps->a);ps->a = NULL;ps->top = 0;ps->capacity = 0;
}
//入栈
void StackPush(ST* ps, STDatatype x)
{assert(ps);if (ps->top == ps->capacity){STDatatype* tmp = (STDatatype*)realloc(ps->a, ps->capacity * 2 * sizeof(STDatatype));if (tmp == NULL){perror("realloc fail");exit(-1);}ps->a = tmp;ps->capacity *= 2;}ps->a[ps->top] = x;ps->top++;
}
//出栈
void StackPop(ST* ps)
{assert(ps);assert(!StackEmpty(ps));ps->top--;
}
//获取栈顶元素
STDatatype StackTop(ST* ps)
{assert(ps);assert(!StackEmpty(ps));return ps->a[ps->top - 1];
}
//判断栈是否为空，若为空，则返回非零，若不为空，则返回零
bool StackEmpty(ST* ps)
{assert(ps);return ps->top == 0;
}
//获取栈中的元素个数
int StackSize(ST* ps)
{assert(ps);return ps->top;
}

当栈顶初始化为-1时，代码如下：

top先++，再放数据

//初始化栈
void StackInit(ST* ps)
{assert(ps);ps->a = (STDatatype*)malloc(sizeof(STDatatype) * 4);if (ps->a == NULL){perror("malloc fail");exit(-1);}ps->top = -1;ps->capacity = 4;
}
//销毁栈
void StackDestroy(ST* ps)
{assert(ps);free(ps->a);ps->a = NULL;ps->top = -1;ps->capacity = 0;
}
//入栈
void StackPush(ST* ps, STDatatype x)
{assert(ps);if (ps->top + 1 == ps->capacity){STDatatype* tmp = (STDatatype*)realloc(ps->a, ps->capacity * 2 * sizeof(STDatatype));if (tmp == NULL){perror("realloc fail");exit(-1);}ps->a = tmp;ps->capacity *= 2;}ps->top++;ps->a[ps->top] = x;
}
//出栈
void StackPop(ST* ps)
{assert(ps);assert(!StackEmpty(ps));ps->top--;
}
//获取栈顶元素
STDatatype StackTop(ST* ps)
{assert(ps);assert(!StackEmpty(ps));return ps->a[ps->top];
}
//判断栈是否为空，若为空，则返回非零，若不为空，则返回零
bool StackEmpty(ST* ps)
{assert(ps);return ps->top == -1;
}
//获取栈中的元素个数
int StackSize(ST* ps)
{assert(ps);return ps->top + 1;
}

二、队列的实现

队列是一种特殊的线性表，只允许在一端进行插入数据操作，在另一端进行删除数据操作，进行插入数据的一端称为队尾，进行删除数据的一端称为队头。

创建一个栈：

typedef int QDataType;
typedef struct QueueNode
{QDataType data;struct QueueNode* next;
}QNode;typedef struct Queue
{QNode* head;QNode* tail;int size;
}Queue;

代码实现：

//初始化队列
void QueueInit(Queue* pq)
{assert(pq);pq->head = NULL;pq->tail = NULL;pq->size = 0;
}
//销毁队列
void QueueDestroy(Queue* pq)
{assert(pq);QNode* cur = pq->head;while (cur){QNode* del = cur;cur = cur->next;free(del);}pq->head = pq->tail = NULL;pq->size = 0;
}
//入队
void QueuePush(Queue* pq, QDataType x)
{assert(pq);QNode* newnode = (QNode*)malloc(sizeof(QNode));if (newnode == NULL){perror("malloc fail");exit(-1);}newnode->data = x;newnode->next = NULL;if (pq->tail == NULL){pq->head = pq->tail = newnode;}else{pq->tail->next = newnode;pq->tail = newnode;}pq->size++;
}
//出队
void QueuePop(Queue* pq)
{assert(pq);assert(!QueueEmpty(pq));if (pq->head->next == NULL){free(pq->head);pq->head = pq->tail = NULL;}else{QNode* del = pq->head;pq->head = pq->head->next;free(del);}pq->size--;
}
//获取队列头部元素
QDataType QueueFront(Queue* pq)
{assert(pq);assert(!QueueEmpty(pq));return pq->head->data;
}
//获取队列队尾元素
QDataType QueueBack(Queue* pq)
{assert(pq);assert(!QueueEmpty(pq));return pq->tail->data;
}
//判断队列是否为空，若为空，则返回非零，若不为空，则返回零
bool QueueEmpty(Queue* pq)
{assert(pq);return pq->head == NULL && pq->tail == NULL;
}
//获取队列中元素个数
int QueueSize(Queue* pq)
{assert(pq);return pq->size;
}