【栈】3、创建栈

#include<stdio.h>
#include<stdbool.h>
#include<stdlib.h>
#define TYPE int
//#define TYPE biTree*
//#define TYPE char
//#define TYPE Recursion
struct biTree {
    char data;
    struct biTree *lchild;
    struct biTree *rchild;
};
struct Recursion {
    int no;
    int val;
};
struct Stack
{
    TYPE* arr;    //内存首地址
    int  len;    //栈的容量
    int top;     //栈的下标
};
/* --------------以下为实现函数--------------------*/
//创建一个栈
Stack *createStack(int size) {
    struct Stack *stack = (struct Stack*)malloc(sizeof(struct Stack));//给栈分配空间
    stack->arr = (TYPE *)malloc(sizeof(TYPE)*size);//给内存首地址分配空间，大小用户指定
    stack->len = size;//栈容量
    stack->top = -1;//栈顶下标，当前无元素，故为-1
    return stack;
}
//判断栈满
bool full(Stack *stack) {
    return stack->top + 1 >= stack->len;
}
//判断栈空
bool empty(Stack *stack) {
    return stack->top == -1;
}
//入栈
bool push(Stack *stack, TYPE p) {
    if (full(stack)) return false;
    *(stack->arr + ++stack->top) = p;
    return true;
}
//出栈
bool pop(Stack *stack) {
    if (empty(stack)) return false;
    stack->top--;
    return true;
}
//查看栈顶元素
TYPE top(Stack *stack) {
    if (empty(stack)) return NULL;
    return *(stack->arr + stack->top);
}
//销毁
void destory(Stack *stack) {
    free(stack->arr);
    free(stack);
}
//判断是否含有某个元素
bool contain(Stack *stack, TYPE r) {
    if (empty(stack)) return false;
    for (int i = stack->top; i >= 0; i--) {
        if (r == *(stack->arr + i) ){//疯了，我居然把==写成了=
            return true;
        }
    }
    return false;
}