資料結構中構建順序表

標籤：資料結構   c語言   struct   malloc   

     順序表指的是資料元素在記憶體中連續分配地址的數組，由於指標無法指出數組長度，編譯時間不會報錯，所有用結構體來表示一個順序表：

順序表用C語言的表示方法如下：

<span style="font-family: Arial, Helvetica, sans-serif;">  #define OK 1</span>

  #define ERROR -1  typedef int elem_type;

  typedef int Statue; //  int Arrylength;   typedef struct sqlist   {   elem_type  *Arry;   int  Arrylength;   } Sqlist;    //建立一個空表  Statue Create_Sqlist(Sqlist *&S)   {    //S->Arry = (elem_type *) malloc(MaxSize*sizeof(elem_type));//L = (sqlist *)malloc(sizeof(sqlist));   // L->data = (char *)malloc(maxsize);    S = (Sqlist *)malloc(sizeof(Sqlist)); S->Arry = (elem_type *)malloc(MaxSize);   if(!S->Arry)   {   return ERROR;   }   else   {   S->Arrylength = 0;   return OK;    }   }//順序表賦初始值  void   Init_Sqlist(Sqlist *&S)  {  int i;  for(i=0;i<20;i++)  {     S->Arry[i]=rand()%100;        S->Arrylength++;   }  }  //在第i個位置添加一個元素m  Statue Insert_Sqlist(Sqlist *&S,int i,int InsertNum){  if(i<=0 && i>S->Arrylength)   return ERROR;  else  {  int j;  for(j=0;j<=S->Arrylength-i;j++)   S->Arry[S->Arrylength-j]=S->Arry[S->Arrylength-1-j];    //i以後元素往後移動一位   S->Arry[i-1]=InsertNum;   S->Arrylength++;   return OK;  }}//將第i個元素刪除  Statue Delete_Sqlist(Sqlist *&S,int i){  if(i<=0 && i>S->Arrylength)   return ERROR;  else  {  int j;  for(j=0;j<=S->Arrylength-i;j++)    S->Arry[i-1+j]= S->Arry[i+j];   S->Arrylength--;   return OK;  }}//刪除值為x的元素  void DeleteX_Sqlist(Sqlist *&S,int x){  int i;  for(i=0;i< S->Arrylength;i++)      {      if(x == S->Arry[i])      {      //Delete_Sqlist( *S, i);int j;      for(j=0;j<=S->Arrylength-i;j++)        S->Arry[i+j]= S->Arry[i+j+1];      S->Arrylength--;      }      }}  //列印函數  void print(Sqlist *&S)  {     int m;for(m=0;m<S->Arrylength;m++){cout<<setw(4)<<S->Arry[m];if((m+1)%4==0)cout<<endl;     }  }int main(){Sqlist *p1;    Create_Sqlist( p1);cout<<"建立順序表is OK"<<endl;    Init_Sqlist(p1);cout<<"初始化順序表is OK，資料如下："<<endl;print(p1); int i,InsertNum;cout<<"輸入兩個如下：";cin>>i;cin>>InsertNum;cout<<"插入數操作如下：在第"<<i<<"行插入數字"<<InsertNum<<"後。結構顯示如下："<<endl;Insert_Sqlist( p1, i, InsertNum);print(p1);int k;cout<<endl;cout<<"輸入一個數如下:";cin>>k;cout<<"刪除數操作如下："<<endl;cout<<"想要刪除第"<<k<<"個數 顯示如下："<<endl;    Delete_Sqlist(p1,k);    print(p1);int j;cout<<"輸入一個數"<<endl;    cin>>j;cout<<"刪除指定數操作如下：輸入想要刪除的數是："<<j<<"    結果顯示如下："<<endl;    DeleteX_Sqlist(p1,j);print(p1);while(1);return 0;}

        顯示結果如下：

                分析比較下面程式碼片段的差別：

A段——建立空表沒有bug的代碼：

 typedef struct sqlist   {   elem_type  *Arry;   int  Arrylength;   } Sqlist;    //建立一個空表  Statue Create_Sqlist(Sqlist *&S)   {        S = (Sqlist *)malloc(sizeof(Sqlist)); S->Arry = (elem_type *)malloc(MaxSize);   }

B段——建立空表出現bug的代碼：

typedef struct sqlist   {   elem_type  Arry[MaxSize];   int  Arrylength;   } Sqlist;    //建立一個空表  Statue Create_Sqlist(Sqlist *S)   {    S->Arry = (elem_type *) malloc(MaxSize*sizeof(elem_type));  }