数据结构：第七章学习小结

1 int Search(SSTable ST, KeyType key) 
2 { 
3     for(i=1;i<=ST.length;i++)
4     {
5         if(key==ST.R[i].key) return i;
6      }
7     return 0;//若未查找到则返回0
8 }

1 //避免查找过程中每次检测整个表是否查找完毕的步骤
2 //在数据量大能有效减少查找时间
3 int Search(SSTable ST, KeyType key) 
4 {
5     ST.R[0].key = key; //把待查关键字key存入表头,起监视哨作用
6     for(i=ST.length; ST.R[i].key!=key; --i );
7     return i; //若查找到则返回其下标，若未查找到则返回0
8 }

 1 int Search(SSTable ST, KeyType key, int low, int high) 
 2 {
 3     if(low <= high){
 4         mid = (low+high) / 2;
 5         if(key == ST.R[mid].key) 
 6               return mid;
 7         else if(key < ST.R[mid].key)
 8               return Search(ST,key,low,mid-1);//递归查找左区间
 9         else 
10              return Search(ST,key,mid+1,high);//递归查找右区间
11     }
12     return 0;//若未查找到则返回0
13 }

 1 int Search(SSTable ST, KeyType key) 
 2 {
 3     int low = 1, high = ST.length;//置查找区间初值
 4     while(low <= high) 
 5     { 
 6         mid = (low+high) / 2; 
 7         if(key == ST.R[mid].key) 
 8             return mid;//找到待查元素
 9         else if(key < ST.R[mid].key) 
10             high = mid-1; //继续在前一子表进行查找
11         else 
12             low = mid + 1; //继续在后一子表进行查找
13     }
14     return 0; //表中不存在待查元素则返回0 
15 }

1 Tree Search(Tree T, KeyType key) 
2 {
3     if((T==NULL) || key==T->data.key)//若树空或查找到，返回当前结点
4         return T; 
5     else if(key < T->data.key) //在左子树中继续查找 
6         return SearchBST(T->lchild, key); 
7     else //在右子树中继续查找 
8         return SearchBST(T->rchild, key); 
9 }

 1 void Insert(Tree &T, ElemType key ) 
 2 {
 3     if (T == NULL)
 4     {//树为空则作为根结点 
 5         s = new Node; 
 6         s->data = key; 
 7         s->lchild = s->rchild = NULL; 
 8         T = s; 
 9     }
10     
11     if (key == T.data) return; //查找成功则退出 
12     else if (key < T.data) //小于当前结点值，递归左子树 
13         Insert(T -> lchild, key); 
14     else if (key > T.data) //大于当前结点值，递归右子树 
15         Insert(T -> rchild, key);
16 }