判断是否为回文数或回文字符

判断一个数是否为回文数：

#include

int fun(int num)

{

int old = num; //必须要保存原数，后面要进行比较

int newnum = 0;

while(num)

{

newnum = ret* 10 + num % 10;

num /= 10;

}

return newnum == old;

}

int main()

{

int ret = fun(1234321);

if(ret == 0)

{

printf("不是回文数\n");

}

else if(ret == 1)

{

printf("回文数\n");

}

return 0;

}

判断一个字符串是否为回文字符串

#include

#include

int fun(const char *str)

{

const char *start = str;

const char *end = str+strlen(str)-1;

while(start < end)

{

if(*start == *end)

{

start++;

end--;

}

else

return 0;

}

return 1;

}

int main()

{

char *p = "abcdcba";

int ret = fun(p);

if(ret == 1)

printf("回文字符串\n");

else if(ret == 0)

printf("不是回文字符串\n");

return 0;

}