二分查找

typedef int ElemType;
typedef struct{
    ElemType *elem;//整型指针
    int TableLen;//存储动态数组里边元素的个数
}SSTable;

int Binary_Search(SSTable L,ElemType key)
{
    int low=0,high=L.TableLen-1,mid;
    while(low<=high)
    {
        mid=(low+high)/2;
        if(L.elem[mid]==key)
            return mid;//等于就找到了
        else if(L.elem[mid]>key)
            high=mid-1;
        else
            low=mid+1;
    }
    return -1;
}

哈希查找