#include<stdio.h>
#include<stdlib.h>
typedef int ElementType; /*栈元素类型*/
#define SUCCESS 0
#define FAILURE -1
/*定义栈结构*/
typedef struct StackInfo
{ElementType value; /*栈存储的数据*/struct StackInfo *next; /*指向栈的下一个元素*/
}StackInfo_st;
/*函数声明*/
StackInfo_st *createStack(void);
int stack_push(StackInfo_st *s,ElementType value);
int stack_pop(StackInfo_st *s,ElementType *value);
int stack_top(StackInfo_st *s,ElementType *value);
int stack_is_empty(StackInfo_st *s);
/*创建栈，外部释放内存*/
StackInfo_st *createStack(void)
{StackInfo_st *stack = (StackInfo_st *)malloc(sizeof(StackInfo_st));if(NULL == stack){printf("malloc failed\n");return NULL;} stack->next = NULL;return stack;
}
/*入栈，0表示成，非0表示出错*/
int stack_push(StackInfo_st *s,ElementType value)
{StackInfo_st *temp = (StackInfo_st *)malloc(sizeof(StackInfo_st));if(NULL == temp){printf("malloc failed\n");return FAILURE;}/*将新的节点添加s->next前，使得s->next永远指向栈顶*/temp->value = value;temp->next = s->next;/*这一句是指向栈头部，实际上不用也没有问题*/s->next = temp;return SUCCESS;
}
/*出栈*/
int stack_pop(StackInfo_st *s,ElementType *value)
{/*首先判断栈是否为空*/if(stack_is_empty(s))return FAILURE;/*找出栈顶元素*/*value = s->next->value;/*保存等下需要free的指针*/StackInfo_st *temp = s->next;/*更换栈顶的位置*/s->next = s->next->next;/*释放栈顶节点内存*/if(temp!=NULL)/*先判断指针是否为空*/free(temp);temp = NULL;return SUCCESS;
}
/*访问栈顶元素*/
int stack_top(StackInfo_st *s,ElementType *value)
{/*首先判断栈是否为空*/if(stack_is_empty(s))return FAILURE;*value = s->next->value;return SUCCESS;
}
/*判断栈是否为空，空返回1，未空返回0*/
int stack_is_empty(StackInfo_st *s)
{/*栈顶指针为空，则栈为空*/return s->next == NULL;
}
int main(void)
{/*创建栈*/StackInfo_st *stack = createStack();/*如果栈为空，则压入元素1*/if(stack_is_empty(stack)){int i = 0;for(i = 0 ;i< 23;i++){ printf("push value %d\n",i);stack_push(stack,i);} }/*访问栈顶元素*/int topVal;stack_top(stack, &topVal);printf("top value %d\n",topVal);/*出栈*/int tm = 0;for(tm = 0;tm<25;tm++){int popVal;stack_pop(stack, &popVal);printf("pop value %d %d\n",tm,popVal);}int i = 0;while(SUCCESS == stack_push(stack,i) && i < 5){i++;}printf("top if stack value is %d\n",stack->next->value);/*最后记得将栈内存都释放，可自己尝试实现*/return 0;
}