004、栈的基本操作

#include <stdio.h>
#include <stdlib.h>
#include "math.h"

typedef struct demo
{
    int* base;
    int* top;
    int stacksize;
}sqstack;

/* 创建一个栈 */
int stackInit(sqstack* S,int n)
{
    S->base = (int*)malloc(sizeof(int)*n);
    if(!S->base)
    {
        printf("stack is null!");
        return 0;
    }
    S->top = S->base;
    S->stacksize = n;
    return 1;
}

/* 清空一个栈 */
void clearStack(sqstack* S)
{
    S->top = S->base;
}

/* 销毁一个栈 */
void destroyStack(sqstack* S)
{
    free(S->base);
    S->base = S->top = NULL;
    S->stacksize = 0;
}

/* 入栈 */
#define STACKINSERSIZE 10
int Push(sqstack* S,int data)
{
    if(S->top - S->base >= S->stacksize)
    {
        S->base = (int*)realloc(S->base,(S->stacksize+STACKINSERSIZE)*sizeof(int));
        if(!S->base)    return 0;
        S->top = S->base + S->stacksize;
        S->stacksize = S->stacksize + STACKINSERSIZE;
    }
    *(S->top) = data;
    S->top++;

    return 1;
}

/* 出栈 */
int Pop(sqstack* S,int* data)
{
    if(S->top == S->base)    return 0;
    S->top--;
    *data = *(S->top);
}

int stackLen(sqstack S)
{
    return (S.top-S.base);
}
int main()
{
    sqstack stack1;
    int i,len,sum = 0;
    int c;
    stackInit(&stack1,20);
    clearStack(&stack1);
    
    printf("please inpot 0 or 1
");
//    scanf("%c",&c);
    /* 输入0 or 1字符表示二进制，以 # 结束，例如：1111# */
    while((c = getchar()) != '#')
    {
        /* 入栈 */
        Push(&stack1,c);
//        scanf("%c",&c);
    }
    getchar();
    len = stackLen(stack1);
    printf("
len = %d
",len);
    for(i = 0;i < len;i++)
    {
        /* 出栈 */
        Pop(&stack1,&c);
        /* 计算将二进制转换成10进制 */
        sum = sum + ((c - '0') * (pow(2,i)));
    }
    printf("decimal is %d
",sum);
    destroyStack(&stack1);
    getchar();
    return 0;
}