程序出错 出现subscript requires array or pointer type

include
#include
main()
{
char s[100],ch;
int a=0,b=0,top,i=0;
char *t;
printf("请输入字符串，并以'#'结束!");
gets(s);
top=strlen(s)-2;
t=s;
ch=*s;
while(ch!='#'&&top>=0)
{
if(*(t+top)==ch[i])
{a++;
i++;}
top--;
b++;
}
if(a==b)
printf("该字符串为回文!");
else
printf("该字符串不是回文!");
}

因为你声明时char ch; ch为字符而不是字符数组，因此在语句if(*(t+top)==ch[i])中ch[i]是不正确的
应该改为s[i];

#include "stdio.h" #define num 10 int search (int value[],int key,int low,int high); void main () { int value[num],result,key; int i; for (i=0;i<num;i++) scanf ("%d",&value[i]); printf ("\n enter a key:"); scanf ("%d",&key); result=search(value,key,0,num-1); if (result!=-1) printf ("\nelement %d is at pos:%d\n",key,result); else printf ("\n fail to find %d\n",key); } int search (int value[],int key,int low,int high) { int mid; if (low>high) return -1; mid=((low+high)/2); if ( value[mid]==key ) return mid; if ( key<value[mid] ) return search (value,key,low,mid-1); else return search (value,key,mid+1,high); } 其他地方没什么问题，只是把你的输出方式小小改动了下。。。