关于书下的hash函数有关问题， 来自 数据结构与算法分析-C语言实现

关于书上的hash函数问题， 来自 数据结构与算法分析-C语言实现

C/C++ code

#ifndef _HashSep_H        #define _HashSep_H        struct ListNode;        typedef struct ListNode *Position;        struct HashTbl;        typedef struct HashTbl *HashTable;        HashTable InitializeTable( int TableSize );        void DestroyTable( HashTable H );        Position Find( ElementType Key, HashTable H );        void Insert( ElementType Key, HashTable H );        ElementType Retrieve( Position P );        /* Routines such as Delete are MakeEmpty are omitted */        #endif  /* _HashSep_H */        struct ListNode        {            ElementType Element;            Position    Next;        };        typedef Position List;        /* List *TheList will be an array of lists, allocated later */        /* The lists use headers (for simplicity), */        /* though this wastes space */        struct HashTbl        {            int TableSize;            List *TheLists;   //The Lists是一个指向指向ListNode结构的指针的指针。        };散列表初始化例程        HashTable        InitializeTable( int TableSize )        {            HashTable H;            int i;/* 1*/      if( TableSize < MinTableSize )            {/* 2*/          Error( "Table size too small" );/* 3*/          return NULL;            }            /* Allocate table *//* 4*/      H = malloc( sizeof( struct HashTbl ) );/* 5*/      if( H == NULL )/* 6*/          FatalError( "Out of space!!!" );/* 7*/      H->TableSize = NextPrime( TableSize );   //？            /* Allocate array of lists *//* 8*/      H->TheLists = malloc( sizeof( List ) * H->TableSize );/* 9*/      if( H->TheLists == NULL )/*10*/          FatalError( "Out of space!!!" );            /* Allocate list headers *//*11*/      for( i = 0; i < H->TableSize; i++ )            {/*下面的部分，书上说，在循环中每次进行一词malloc，这样性能不高， *一个好的替换方法是把 行12的部分去掉，而在for循环之前写上如下语句， *H->TheLists[ i ] = malloc( sizeof( struct ListNode ) * H->TableSize ); *是否是要替换掉第8行？不知道应该怎么替换，希望各位前辈能指点一下，先谢过了 *//*12*/          H->TheLists[ i ] = malloc( sizeof( struct ListNode ) );/*13*/          if( H->TheLists[ i ] == NULL )/*14*/              FatalError( "Out of space!!!" );                else/*15*/              H->TheLists[ i ]->Next = NULL;            }/*16*/      return H;        }

C/C++ code

     Position pStart = (ListNode*)malloc( sizeof( struct ListNode ) * H->TableSize );  //一次性分配内存     for ( int j = 0; j < H->TableSize; j++)     {      H->TheLists[j] = pStart+j*sizeof(ListNode);                                   //将各块地址分发给管理头     }