C中自带的排序函数qsort

#define NELEMS(array) (sizeof(array)/sizeof(array[0]))//scmp: string compare of *p1 and *p2//p1 p2是是字符串数组的一个元素的指针。字符串数组char* str[](等价于char** str)int scmp(const void *p1, const void *p2){    char *v1;//字符串    char *v2;    v1 = *(char **)p1;//为什么是char**---因为-q s o r t传递的是数组里元素的地址，    //也就是说，是&str[i](类型为char**)而不是str[i](类型为char*)    //而str[i]是char*    v2 = *(char **)p2;    return strcmp(v1,v2);}//mian    //char* str[] = {{"asd"},{"adf"},{"key"},{"yue"},{"ber"},{"mew"}};    char *str[]={"red","yellow","blue","white","black"};    int N = NELEMS(str);    cout<<"字符串数组的元素个数 = "<<N<<endl;    qsort(str,N,sizeof(str[0]),scmp);                      //C++中是sort()    cout<<"字符串 : "<<endl;    for(int i=0; i<N; i++){        cout<<str[i]<<"  ";    }    cout<<endl;