分块查找算法

问题：明白思想，其他的没什么，记得结构体为指针时一定要动态分配内存。

代码：

#include <iostream>
#include <cstdlib>
 
using namespace std;
#define MAXL 20
typedef struct seq
{
    int key[MAXL];
    int len;
}data;
 
typedef struct table
{
    int start;
    int end;
    int d;
}index[4];
 
int block_search(index s,data *list,int key)         //分块查找
{
    int i=0;
    int j;
    while(i<4&&key>s[i].d)     //确定块的地址
        i++;
    if(i>=4)
        return -1;
 
    for(j=s[i].start;j<=s[i].end;j++)
    {
        if(list->key[j]==key)
            return j;
    }
    if(j>s[i].end)
        return -1;
 
}
 
int  main()
{
    data *list;
    index s;
    int i,j,p;
    int key;
    cout<<"/"<<"分块查找"<<"/"<<endl;
    cout<<"---------------------"<<endl;
    list=(data *)malloc(sizeof(struct seq));
    if(!list)
        cout<<"allocate fail"<<endl;
 
    cout<<"input the len:";
    cin>>list->len;
    for(i=0;i<list->len;i++)
    {
        cin>>list->key[i];
    }
 
    cout<<"output the list:"<<endl;
    for(i=0;i<list->len;i++)
    {
        cout<<list->key[i]<<"  ";
    }
    cout<<endl;
    for(j=0;j<4;j++)
    {
        cin>>s[j].start>>s[j].end>>s[j].d;
    }
 
    cout<<"please input the key:";
    cin>>key;
    p=block_search(s,list,key);
    if(p==-1)
        cout<<"can not find"<<endl;
    else
        cout<<"the key pos is  "<<p<<endl;
    return 0;
 
}