main.c

来自「数据结构源码合集」· C语言 代码 · 共 75 行

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

typedef struct node *link;

struct node
{
	char item;
	link next;
};

link NODE(char item, link next)
{
	link t = malloc(sizeof *t);
	t->item = item;
	t->next = next;

	return t;
}

link head;

void STACKinit(int n)
{
	head = NULL;
}

void push(char item)
{
	head = NODE(item, head);
}

char pop()
{
	char item = head->item;
	link x = head->next;
	free(head);
	head = x;

	return item;
}

int STACKempty()
{
	return head == NULL;
}

void STACKdestory()
{
	while(!STACKempty())
		pop();
}

int main(int argc, char *argv[])
{
	char *a = argv[1];
	int i;
	int N = strlen(a);
	STACKinit(N);
	for(i = 0; i < N; i++)
	{
		if(a[i] == ')')
			printf("%c", pop());
		if(a[i] == '+' || a[i] == '*')
			push(a[i]);
		if(a[i] >= '0' && a[i] <= '9')
			printf("%c", a[i]);
	}
	printf("\n");
	STACKdestory();

	return 0;
}