题解 | #字符串排序#

#include<ctype.h>
#include<stdlib.h>
#include<string.h>
#include<assert.h>
int my_strcmp(const void* elem1,const void* elem2)
{
    assert(elem1&&elem2);
    char ret1 = *(char*)elem1;
    char ret2 = *(char*)elem2;
    if(isupper(*(char*)elem1))//大写变小写
    {
        ret1 = 'a'-'A'+*(char*)elem1;
    }
    if(isupper(*(char*)elem2))//大写变小写
    {
        ret2 = 'a'-'A'+*(char*)elem2;
    }
    return ret1 - ret2;
}
void my_swap(char* elem1,char* elem2,int width)
{
    int i = 0;
    for(i = 0;i<width;i++)
    {
        char temp = *(elem1+i);
        *(elem1+i) = *(elem2+i);
        *(elem2+i) = temp;
    }
}
void my_bubblesort(void* arr,int len,int width,int(*p)(const void*,const void*))
{
    assert(arr);
    int i = 0,j = 0;
    for(i=0;i<len-1;i++)
    {
        for(j = 0;j<len - i - 1;j++)
        {
            int flag = 0;
            while (0 == isalpha(*((char*)arr + j)))//如果当前位置的不是字母
            {
                j++;
                if ('\0' == *((char*)arr + j))
                {
                    break;
                }
            }
            int ret = j+1;
            while(0 == isalpha(*((char*)arr+ret)))//如果下一个位置不是字母,再往下找，直到是字母为止
            {
                ret++;
                if('\0' == *((char*)arr+ret))
                   {
                       flag = 1;
                       break;
                   }
            }
            if(1 == flag)
            {
                break;
            }
            if((*p)((char*)arr+j*width,(char*)arr+ret*width)>0)
            {
                my_swap((char*)arr+j*width,(char*)arr+ret*width,width);
            }
        }
    }
}
int main()
{
    char* arr = (char*)calloc(2000,sizeof(char));
    if(NULL == arr)
    {
        perror("calloc");
        return 0;
    }
    gets(arr);
    my_bubblesort(arr,strlen(arr),sizeof(char),my_strcmp);
    printf("%s",arr);
    int i = 0;
    return 0;
}