#include <stdio.h>
#include <stdlib.h>
typedef struct {
	int top[2], bot[2];	// 栈顶和栈底指针
	int* V;							// 栈数组
	int m;							// 栈最大可容纳数
}DblStack;
// 栈初始化
int InitDblStack(DblStack* S,int m) {
	S->m = m;
	S->V = (int*)malloc(sizeof(int)*m);
	S->bot[0] = -1;
	S->top[0] = -1;
	S->bot[1] = m;
	S->top[1] = m;
	return 1;
}
// 栈空
int DblStackEmpty(DblStack* S) {
		return S->top[1] == S->m || S->top[0] == -1?1:0;
}
// 栈满:栈满只需判断总栈是否满
int DblStackFull(DblStack* S) {
	return S->top[1]-S->top[0]==1? 1 : 0;
}
// 第i号栈，e为入栈元素
int Push(DblStack* S,int i,int e) {
	if (i < 0 || i>1) return 0;
	// 判断栈满
	if (DblStackFull(S)) return 0;
	// 入栈
	if (i) S->top[i]--;
	else S->top[i]++;
	S->V[S->top[i]] = e;
	return 1;
}
int Pop(DblStack *S, int i,int *e) {
	if (i < 0 || i>1) return 0;
	if (DblStackEmpty(S)) return 0;
	*e = S->V[S->top[i]];
	if (i) S->top[i]++;
	else S->top[i]--;
	return 1;
};
int main() {
	DblStack* S;
	S = (DblStack*)malloc(sizeof(DblStack));
	InitDblStack(S,5);
	if (DblStackEmpty(S)) printf("栈空\n");
	Push(S, 0, 0);
	Push(S, 0, 1);
	Push(S, 0, 2);
	Push(S, 0, 3);
	Push(S, 0, 4);
	int i = 0,e=-1;

	if (DblStackFull(S)) printf("\n栈满\n");
	for (; i < 6; i++) {
		Pop(S, 1, &e);
		printf("%3d", e);
	}
	return 0;
};