#include<stdio.h>
#include<string.h>
#define n 10
typedef struct
{
    char data[n];
    int top;
}seqstack;

void stackinitial(seqstack *ps)
{
    ps->top=-1;
}

int isempty(seqstack *ps)
{
    return ps->top==-1;
}

int isfull(seqstack *ps)
{
    return ps->top>=n-1;
}

void push(seqstack *ps,int e)
{if(isfull(ps))
{
    printf("栈已满\n");
    exit(1);
}
ps->data[++ps->top]=e;
}

char pop(seqstack *ps)
{
    if(isempty(ps))
    {
        printf("空栈！\n");
        exit(1);
    }
    return ps->data[ps->top--];
}

int pair(char a[])
   {
    int i=0;
    char ch,temp;
    seqstack q;
    stackinitial(&q);
    while(ch=a[i++]!='\0')
        push(&q,ch);
        i=0;
    while(!=isempty(&q))
    {
        temp=pop(&q);
        if(temp!=a[i++])
            return 0;
    }
    return 1;
  }

 void main()
 {  
    char a[n];
    int i,j;
    printf("input string\n");
    for(i=0;i<n;i++)
        scanf("%c",&a[i]);
    j=pair(a);
    if(j==1)
        printf("是回文：\n");
    for(i=0;i<n;i++)
        printf("%c",a[i]);
 }

老是出现这样的错误: warning C4013: 'exit' undefined; assuming extern returning int
D:\Vc\c程序\c语言\c++\03.c(53) : error C2059: syntax error : '!='
D:\Vc\c程序\c语言\c++\03.c(59) : error C2059: syntax error : 'return'
D:\Vc\c程序\c语言\c++\03.c(60) : error C2059: syntax error : '}'
Error executing cl.exe.

03.obj - 3 error(s), 1 warning(s)

小弟急啊！望大侠帮忙看哈