C 棧

 

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>

typedef int StackElementType;
typedef struct StackNode {
    StackElementType data;
    struct StackNode *next;
} StackNode;

typedef struct Stack {
    int size;
    StackNode *front;
} Stack;

Stack *CreateStack()
{
    Stack *stack = (Stack *)malloc(sizeof(Stack));
    stack->size = 0;
    stack->front = NULL;
    return stack;
}

bool IsEmptyStack(Stack *stack)
{
    if (stack->front == NULL) {
        return true;
    }
    return false;
}

void PushStack(StackElementType data, Stack *stack)
{
    StackNode *stackNode = (StackNode *)malloc(sizeof(StackNode));
    stackNode->data = data;
    stackNode->next = stack->front;
    stack->front = stackNode;
    stack->size += 1;
    return;
}

void PopStack(Stack *stack)
{
    StackNode *stackNode = NULL;
    if (IsEmptyStack(stack) == true) {
        return;
    }
    stack->size -= 1;
    stackNode = stack->front;
    stack->front = stack->front->next;
    free(stackNode);
    stackNode = NULL;
}

StackElementType GetFront(Stack *stack)
{
    if (IsEmptyStack(stack) == false) {
        return stack->front->data;
    }

    return 0;
}

void CleanStack(Stack *stack)
{
    StackNode *stackNode = stack->front;
    StackNode *stackTempNode = NULL;

    while (stackNode != NULL) {
        stack->size -= 1;
        stackTempNode = stackNode->next;
        free(stackNode);
        stackNode = stackTempNode;
    }
    stack->front = stackNode;
}

void TraverseStack(Stack *stack)
{
    StackNode *stackNode = stack->front;

    if (IsEmptyStack(stack) == true) {
        return;
    }

    while (stackNode != NULL) {
        printf("%d ", stackNode->data);
        stackNode = stackNode->next;
    }
    printf("\n");
}

int main()
{
    Stack *stack = CreateStack();
    PushStack(1, stack);
    PushStack(2, stack);
    PushStack(3, stack);
    PushStack(4, stack);
    PushStack(5, stack);
    PushStack(6, stack);
    TraverseStack(stack);
}