stack2.c

来自「自己做的常用库和实现的数据结构。public domain.」· C语言 代码 · 共 50 行

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

typedef struct a {
	int x;
	struct a *next;
} A;

A *top;

void push(int c);
A *pop(A *p);

int main(void)
{
	int c;
	while( (c = getchar()) != EOF ) {
		if(c == '[' || c == ']' || c == '{' || c == '}' || c == '(' || c == ')')
		push(c);
	}
	while(top != NULL)
		top = pop(top);
	puts("");
	return EXIT_SUCCESS;
}

void push(int c)
{
	A *p;
	static int cnt=0;
	if( (p = malloc(sizeof(A))) == NULL ) {
		fprintf(stderr, "Fatal: mem alloc failed !");
		exit(EXIT_FAILURE);
	}
	p->x = c;
	if(cnt++ == 0)
		p->next = NULL;
	else p->next = top;
	top = p;
}

A *pop(A *p)
{
	A *t;
	printf("%c", p->x);
	t = p->next;
	free(p);
	return t;
}