判断回文数、回文字符串（从左边读和从右边读一样）

1.判断一个数是不是回文数,如："123321"

#include <stdio.h>

int main()
{
                 int m=1234;  //m是要判断的数
                 int n=0;  //n是反转后的数
                 int ret=m;
                 while(m)
                {
                  n=n*10+m%10;
                  m/=10;
                }
                 if(ret==n)
                {
                  printf( "Yes!\n");
                }
                 else
                {
                  printf( "No!\n");
                }
                system( "pause");
  return 0;
}

2.判断一个字符串是不是回文字符串，如："abc1234321cba"

#include <stdio.h>

int main()
{
  char *str= "12355321";
  char *start=str;
  char *end=str+strlen(str)-1;
  while(start<end)
  {
    if(*start==*end)
                {
                  start++;
                  end--;
                }
                 else
                {
                  printf( "No!\n");
                  system( "pause");
                  return 0;
                }
  }
  printf("Yes!\n");
  system("pause");
  return 0;
}

转载于:https://blog.51cto.com/ljy789/1707263