回文的概念：顺读和倒读是一样的
比如：12321
madam
上海自来水来自海上
1.法一
#include<stdio.h>
#include<string.h>
int main()
{
char s[100] ;
gets(s);
int start = 0, end = strlen(s) - 1;
int flag = 1;
while (start <= end && 1 == flag)
{
flag = (s[start] == s[end]);
start++;
end--;
}
if (1 == flag)
printf("%s是回文",s);
else
printf("%s不是回文",s);
return 0;
}
2.法二
#include<stdio.h>
#include<string.h>
int main()
{
char s[100] ;
gets(s);
int start = 0, end = strlen(s) - 1;
int flag = 1;
while (start <= end && 1 == flag)
{
flag = (s[start++] == s[end--]);
}
1 == flag ? printf("%s是回文", s) : printf("%s不是回文", s);
return 0;
}
3.法三
#include<stdio.h>
#include<string.h>
int main()
{
char s[100] ;
gets(s);
int start = 0, end = strlen(s) - 1;
int flag = 1;
while (start <= end && flag == (s[start++] == s[end--]));
1 == flag ? printf("%s是回文", s) : printf("%s不是回文", s);
return 0;
}
