void my_strcpy(char *to,const char *from)

{

    if('\0' == *from){

        *to = '\0';

        return ;

    }

    *to++ = *from++;

    my_strcpy(to,from);

}

//只拷贝n个字符

void my_strncpy(char *to,const char* from,int n)

{

    if( 0 == n || '\0' == *from){

        *to = '\0';

        return ;

    }

    *to++ = *from++;

    my_strncpy(to,from,n-1);

}

//字符串比较

int my_strcmp(const char *src,const char *dest)

{

    if((NULL == src || NULL == dest))

        return err;

    if('\0'==*src && '\0'== *dest)

        return 0;

    if(*src != *dest)

        return ( ((*src - *dest)>0)? 1 : -1 );

    my_strcmp(++src,++dest);

}

//之比较n个字符

int my_strncmp(const char* src,const char *dest,int n)

{

    if((NULL == src || NULL == dest))

        return err;

    if(0 == n)

        return 0;

    if(*src != *dest)

        return ( ((*src-*dest)>0)? 1 : -1 );

    my_strncmp(++src,++dest,--n);

}

//过滤掉重复的字符

void word_filter(char *src)

{

    if(*src == '\0')

    {

        printf("\n");

        return ;

    }

    int index = *src;

    if(tmp[index] == 0){

        tmp[index]++;

        printf("%c",*src);

    }

    word_filter(++src);

}

//字符包含问题(小写字符)

int str_include(const char *s1,const char *s2)

{

    if(NULL == s1 || NULL == s2 )

        return err;

    enum ret no=n;

    enum ret yes=y;

    unsigned int bit_map = 0x0;

    for( ; *s2 ; s2++)

        bit_map |= 0x1 << (*s2 - 'a');

    for( ; *s1 ; s1++)

        if(bit_map != (bit_map |= (0x1<<(*s1 - 'a'))))

           return no;

    return yes;

}

//找数组中的最大值

int find_max_value(int *arr,int num)

{

    if(1==num)

        return arr[0];

    int max = find_max_value(arr+1,num-1);

    if(max<arr[0])

        max=arr[0];

    return max;

}

//字符串转置

void str_nizhi(char *str,int start,int end)

{

    if(start>=end)

        return ;

    char ch=*(str+start);

    *(str+start) = *(str+end);

    *(str+end) = ch;

    str_nizhi(str,start+1,end-1);

}

//利用循环求字符串的长度

int fun_strlen(const char *src)

{

    int len=0;

    for( ; *src++; len++);

    return len;

}

//递归实现字符串的长度统计

int ret_str_len(const char *src)

{

    if(*src=='\0')

        return 0;

    return (ret_str_len(++src)+1);

}

//统计ch 中1的个数

int ch_tell(unsigned char ch)

{

    if(ch)

    {

        if(ch&0x01)

            return (ch_tell(ch>>1)+1);

        else

            return ch_tell(ch>>1);

    }

    else

        return 0;

}

//如ch :0x00 到 0xff (0~255)中有多少偶数个1(00000000:0个1、00001001:2个1)的数

int fun_tell(void)

{

    unsigned char ch = 0x0;

    int sum = 0;

    for( ; ; )

    {

        if(ch_tell(ch)%2 == 0)

            sum++;

        if(ch == 0xff)

            break ;

        ch = ch+1;

    }

    return sum;

}

//找数组中相同的值(数值不能大于数组的大小)

#if 1

int get_same_value1(int *arr,int len)

{

    if(NULL == arr || len<=0)

        return err;

    int i=0, *new_array =(int *)malloc(sizeof(int)*len);

    if(new_array == NULL)

        return err;

    //memset(new_array,-1,len);

    for( ; i<len; i++)

        new_array[i]=-1;

    for( i=0 ; i<len ; i++)

    {

        if(new_array[arr[i]] == -1)

            new_array[arr[i]] = arr[i];

        else

            return arr[i];

    }

    free(new_array);

    return 0;

}

#endif

int get_sum(int a, int b)

{

    if(b == 0)

        return a;

    int aa = a^b;

    int bb = (a&b)<<1;

    return get_sum(aa,bb);

}

void zhe_ban_insert_sort(int *arr,int len)

{

    if(NULL == arr || len<=0)

        return ;

    int tmp = 0;

    int i = 0,start=0,end=0,middle=0,j=0;

    for(i=1 ; i<len ; i++)

    {

        tmp = arr[i];

        start = 0;

        end = i-1;

        while(start<=end)

        {

            middle = (start+end)/2;

            if(arr[middle]>arr[i])

                end = middle-1;

            else

                start=middle+1;

        }

        for(j=i-1; j>=start; j--)

            arr[j+1]=arr[j];

        arr[start]=tmp;

    }

}

static inline void get_size(void)

{

    char str[] = "hello";

    char *pt = str ;

    char *ptr= NULL;

    void *p = malloc(100);

    int i =10;

    printf("sizeof str is %d\nstrlen of str is %d\n",sizeof(str),fun_strlen(str));//6,5

    printf("sizeof pt is %d\nstrlen of pt is %d\n",sizeof(pt),fun_strlen(pt));//4,5

    printf("sizeof ptr is %d\n",sizeof(ptr));//4

    printf("sizeof p is %d\n",sizeof(p));//4

    printf("sizeof i is %d\n",sizeof(i));//4

    return ;

}

void *str_str(const char *s1,const char *s2,int (*ncmp)(const char *,const char *,int))

{

    if(NULL == s2 || s2 == NULL)

        return NULL;

    int len1 = ret_str_len(s1);

    int len2 = ret_str_len(s2);

    if(len1<len2)

        return NULL;

    int i = 0;

    for( ; i<len1&&(len1-i>=len2) ; i++){

        if(!ncmp(s1+i,s2,len2))

            return s1+i;

    }

    return NULL;

}