先消除输入字符串的前后空格，再判断是否是“回文”

#include <stdio.h>
#include <string.h>
int main(void)
{
  char s[80], ch, *p, *q;
  int i, j, n;
  gets(s);
  p =s;
  while ( *p == ' ')  
	p++;
  n = strlen(s);
  q = s+n-1;
  while ( *q == ' ') 
  q--;
  while ( p<=q && *p ==*q)
  {
    p++;
    q--;
  }
  if ( p<q )
    printf("NO\n");
  else
    printf("YES\n");
  return 0;
}