关于C的一些的Code Snippet

something about pointer,void *,and generic function 

内容比较简单，但是考虑到函数的通用性后，看出还是比较有意思的。

需要注意的字符串的交换以及字符串的比较，同其它语言的实现，差异还是比较大的，

使用了指向指针的指针~~~~~~~~~~~~~~~~·

SWAP(INT *A,INT *B)
{
 INT TEMP;
 TEMP= *A;
 *A=*B
 *B=TEMP;
 }


void * swap(void * vp1,void * vp2,int size)
{
    char buffer[size];

    memcp(buffer,vp1,size);
    memcp(vp1,vp2,size);
    memcp(vp2,buffer,size);
}

think
int a,int b
swap(&a,&b,sizeof(int));

int a=4;
short b4;
swap(&a,&b,sizeof(int));


think deep now ,
char * h=strdup("abcd");
char * w=strdup("efghaisis");
so ,if you want to exchage this char ?what would you like to do ?
can you tell the difference below?
SWAP(&H,&W,SIZEOF(CHAR *));
SWAP(H,W,SIZEOF(CHAR *));

INT * LSERACH(INT A,
                            INT ARR[],
                            INT N)
                            {
                            FOR( I=0 ; I<N ; I++)
                             IF ( A == ARR[I])
                             RETURN I;

                             RETURN -1

                            }

VOID * LSEARCH(VOID * KEY,
                             VOID * BASE,
                             INT  N,
                             INT ELIEMENTSIZE

{
    FOR (INT I= 0; I<N ; I++)
{
        VOID * ELEMENTADDR =(CHAR *)BASE +I*ELEMENTSIZE;
        IF MEMCMP(KEY,ELEMENTADDR,
SIZEOF(ELEMENTSIZE) ) == 0
        RETURN ELEMENTADDR
}
RETURN NULL;
}
VOID * LSEARCH(VOID * KEY,
                            VOID *BASE,
                            INT IN,
                            INT ELEMENTSIZE,
                            INT (*COMFN)(VOID *,VOID *)
                            )
{
    FOR (I =0 ;I< N; I++) {
    VOID * ELEMENTADDR = (CHAR *) BASE + I*ELEMENTSIZE;
    IF (COMFN(KEY,ELEMENTADDR) == 0 )
    RETURN ELEMENTADD;
    }
    RETURN NULL;
INT A[]={1,4,8,0,6,9};
INT N=6;
KEY=6
LSEARCH(6,A,6,INTCMP)



    INT INTCMP(VOID * ELEMENT1,
               VOID * ELEMENT2)
               {
               INT * P1=ELEMENT1;
               ITN * P2=ELEMENT2;
               RETURN *P1-*P2;
               }

    BUT WHAT IF CHARCMP?
  CHAR *NOTES={"ABC","EFG","HIGHII","E","D"}
  CHAR * KEYNOETE="EB";
  CHAR **FOUND
  LSERACH(&KEYNOTE,NOTES,6,SIZEOF(CHAR *),STRCMP)
  ? STRCMP?
INT STRCMP(VOID * P1,
           VOID * P2)
           {
           CHAR * S1= *(CHAR **) P1;
           CHAR * S2=*(CHAR **) P2;
           RETURN STRCMP(S1,S2);
           }