73b78d8700
📝 文档(main.c)：增加了默认返回值-1以处理操作符优先级的情况 🐛 修复(main.c)：修改st_push函数调用参数类型，解决编译警告 📦 部署(sqlist.c)：为sqlist_union函数添加了缺少的返回语句
150 lines
2.5 KiB
C
150 lines
2.5 KiB
C
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
|
|
#include "sqstack.h"
|
|
|
|
// !!! 课程不完整，程序未写完
|
|
// TODO: snum和sop需要不同的datatype
|
|
|
|
static void compute(sqstack *snum, int *op)
|
|
{
|
|
datatype n1, n2, n;
|
|
|
|
st_pop(snum, &n2);
|
|
st_pop(snum, &n1);
|
|
|
|
switch (*op)
|
|
{
|
|
case '+': n = n1 + n2; break;
|
|
case '-': n = n1 - n2; break;
|
|
case '*': n = n1 * n2; break;
|
|
case '/': n = n1 / n2; break;
|
|
|
|
default: exit(1);
|
|
}
|
|
st_push(snum, &n);
|
|
}
|
|
|
|
static void deal_bracket(sqstack *snum, sqstack *sop)
|
|
{
|
|
datatype old_op;
|
|
|
|
st_top(sop, &old_op);
|
|
|
|
while (old_op != '(')
|
|
{
|
|
st_pop(sop, &old_op);
|
|
compute(snum, &old_op);
|
|
st_top(sop, &old_op);
|
|
}
|
|
|
|
st_pop(sop, &old_op);
|
|
}
|
|
|
|
static int get_pri(int op)
|
|
{
|
|
switch (op)
|
|
{
|
|
case '(': return 0;
|
|
case '+':
|
|
case '-': return 1;
|
|
case '*':
|
|
case '/': return 2;
|
|
default: return -1;
|
|
}
|
|
}
|
|
|
|
|
|
static void deal_op(sqstack *snum, sqstack *sop, char op)
|
|
{
|
|
datatype old_op;
|
|
|
|
if (st_isempty(sop) || op == '(')
|
|
{
|
|
st_push(sop, (datatype *)&op);
|
|
return;
|
|
}
|
|
|
|
st_top(sop, &old_op);
|
|
|
|
if (get_pri(op) > get_pri(old_op))
|
|
{
|
|
st_push(sop, (datatype *)&op);
|
|
return;
|
|
}
|
|
|
|
while (get_pri(op) <= get_pri(old_op))
|
|
{
|
|
st_pop(sop, &old_op);
|
|
compute(snum, &old_op);
|
|
if (st_isempty(sop))
|
|
break;
|
|
|
|
st_top(sop, &old_op);
|
|
}
|
|
st_push(sop, (datatype *)&op);
|
|
}
|
|
|
|
|
|
int main( )
|
|
{
|
|
int i;
|
|
char str[] = "(11+3)*2-5";
|
|
sqstack *snum, *sop;
|
|
int value = 0;
|
|
int flag = 0;
|
|
int old_op;
|
|
|
|
snum = st_create( );
|
|
if (NULL == snum)
|
|
exit(1);
|
|
|
|
sop = st_create( );
|
|
if (NULL == sop)
|
|
exit(1);
|
|
|
|
while (str[i] != '\n')
|
|
{
|
|
if (str[i] >= '0' && str[i] <= '9')
|
|
{
|
|
value = 10 * value + (str[i] - '0');
|
|
flag = 1;
|
|
}
|
|
else // is a op
|
|
{
|
|
if (flag)
|
|
{
|
|
st_push(snum, &value);
|
|
flag = 0;
|
|
value = 0;
|
|
}
|
|
|
|
if (str[i] == ')')
|
|
{
|
|
deal_bracket(snum, sop);
|
|
}
|
|
else // ( + - * /
|
|
{
|
|
deal_op(snum, sop, str[i]);
|
|
}
|
|
}
|
|
i++;
|
|
}
|
|
|
|
if (flag)
|
|
st_push(snum, &value);
|
|
|
|
while (!st_isempty(sop))
|
|
{
|
|
st_pop(sop, &old_op);
|
|
compute(snum, &old_op);
|
|
}
|
|
|
|
|
|
|
|
|
|
st_destroy(snum);
|
|
st_destroy(sop);
|
|
|
|
exit(0);
|
|
} |