linear&binary search

void *lsearch(void* key,void base,int n,int elemSize, int (*cmpfn)(void *,void *)) { for(int i<0;i<n;i++) { void* elemAddr=(char*)base+i*elemSize; //要显式指明指针类型 if(cmpfn(key,elemAddr)==0)//callback return elemAddr; } return NULL; } int array[]={4,2,3,7,11,6}; int size=6; int number=7; int* found=lsearch(&member,array,6,sizeof(int)，intCmp); if(found==NULL){...} else{...} int intCmp(void* elem1,void* elem2) { int* ip1=elem1; int* ip2=elem2; return *ip1- *ip2; }

有时候array是指针数组那么cmp要跳两次

char *notes={"Ab","F#","B","Gb","D"} char *favoritenote="Eb" char **found= //两个*是为了让机器意识到要跳两次 lsearch(&favoriteNote,notes,5,sizeof(char *),StrCmp) //void*不可解引用，void**可以 int StrCmp(void* ip1,void* ip2) { char* s1=*(char **)vp1; /* char *s1=(char *)vp1; 对应lsearch(favoriteNote,notes,5,sizeof(char *),StrCmp) */ char* s2=*(char **)vp2; return strcmp(s1,s2); }

函数与方法(成员函数)的不同在于方法有this指针 静态方法没有this指针

void *bsearch(void* key,void* base,int n,int elemsize,int (*cmp)(void *,void*))

stack

stack.h

typedef struct{ int* elems； int logicallen;//当前元素个数 int alloclength;//最大容量 }stack; void StackNew(stack* s); void StackDespose(stack* s); void StackPush(stack* s,int value); int StackPop(stack* s); stack s; StackNew(&s); for(int i=0;i<5;i++) { StackPush(&s,i); } SatckDispose(&s); void StackNew(stack *s) { s->logicallen=0； s->alloclen=4; s->elems=malloc(4*sizeof(int)); assert(s->elems!=NULL); }