求帮忙修改c++程序,下面是用栈计算后辍表达式值的程序，请把错误和为什么错写出来，感激不尽

Question

#include"stdio.h"
#include"string.h"
#include"malloc.h"
struct seqstack
{
int maxnum;
int t;
struct seqstack *s;
};
typedef struct seqstack *pseqstack;
pseqstack creatnullstack(pseqstack pastack,int m)
{
pastack=(pseqstack)malloc(sizeof(struct seqstack));
if(pastack!=NULL)
{
pastack->s=(struct seqstack*)malloc(sizeof(struct seqstack)*m);
if(pastack->s)
{
pastack->maxnum=m;
pastack->t=-1;
return pastack;
}
else
free(pastack);
}
else
printf("out of space!");
return 0;
}
pseqstack push(pseqstack pastack,int x)
{
if(pastack->t>=maxnum)
printf("overflowed!\n");
else
{
pastack->t=pastack->t+1;
pastack->s[pastack->t]=x;
}
}
pseqstack top(pseqstack pastack)
{
if(pastack->t=-1)
printf("undefflowde!\n");
else
{
return (pastack->s[pastack->t])
pastack->t=pastack->t-1;
}
}
int calculation(String B,pseqstack pastack)
{
char a[];
int i,n,a,b,c;
strcpy(a[],B);
n=strlen(B);
for(i=0;i<n;i++)
{
if(a[i]!='+'&&a[i]!='-'&&a[i]!='*'&&a[i]!='/'&&a[i]!='#')
push(pseqstack pastack,a[i]);
else
{
a=top(pastack);
b=top(pastack);
}
if(a[i]=='+')
d=a+b;
if(a[i]=='-')
d=b-a;
if(a[i]=='*')
d=a*b;
if(a[i]=='/')
d=b/a;
push(pastack,d);
}
printf("%d",pastack->s[pastack->t]);
}
main()
{
pseqstack pastack1=creatnullstack(pseqstack pastack,int 100);
String b;
printf("以#为结束，例如，输入2 3，请输入2 3#");
printf("请输入后辍表达式:");
scanf("%s",b);
calculation(string b,pseqstack pastack1);
}

Answer 1

你的代码只要支持1位数的加减乘除吗？

你的代码错误很多，声明和调用混乱，还有一些其他语法和逻辑错误。我时间不多，只改了程序，没时间加注释和说明了。你使用UltraCompare对比程序查找修改部分吧。

#include "stdio.h"
#include "stdlib.h"
#include "string.h"
#include "malloc.h"

typedef int DataType;
struct seqstack
{
int maxnum;
int t;
DataType *s;
};
typedef struct seqstack *pseqstack;
pseqstack creatnullstack(pseqstack pastack,int m)
{
pastack=(pseqstack)malloc(sizeof(struct seqstack));
if(pastack!=NULL)
{
pastack->s=(DataType*)malloc(sizeof(DataType)*m);
if(pastack->s)
{
pastack->maxnum=m;
pastack->t=-1;
return pastack;
}
else
free(pastack);
}
else
printf("out of space!");
return 0;
}
int push(pseqstack pastack,DataType x)
{
if(pastack->t >= pastack->maxnum)
{
printf("overflowed!\n");
return 0;
}
else
{
pastack->t=pastack->t+1;
pastack->s[pastack->t]=x;
return 1;
}
}
int pop(pseqstack pastack,DataType &x)
{
if(pastack->t==-1)
{
printf("undefflowde!\n");
return 0;
}
else
{
x=pastack->s[pastack->t];
pastack->t=pastack->t-1;
return 1;
}
}
int calculation(char A[],pseqstack pastack)
{
int i,n,a,b,d;
n=strlen(A);
for(i=0;i<n;i++)
{
if(A[i]=='#')
{
break;
}
else if(A[i]!='+'&&A[i]!='-'&&A[i]!='*'&&A[i]!='/'&&A[i]!='#')
{
push(pastack,A[i]-'0');
}
else
{
pop(pastack,a);
pop(pastack,b);
if(A[i]=='+')
d=a+b;
else if(A[i]=='-')
d=b-a;
else if(A[i]=='*')
d=a*b;
else if(A[i]=='/')
d=b/a;
push(pastack,d);
}
}
printf("%d",pastack->s[pastack->t]);
return 1;
}

int main()
{
pseqstack pastack1=creatnullstack(pastack1,100);
char b[100];
printf("以#为结束，例如，输入2+3，请输入23+#");
printf("请输入后辍表达式:");
scanf("%s",b);
calculation(b,pastack1);
system("pause");
return 0;
}