验证分块查找算法

#include
#define MAXL 100    //数据表的最大长度
#define MAXI 20     //索引表的最大长度
typedef int KeyType;
typedef char InfoType[10];
typedef struct
{
    KeyType key;                //KeyType为关键字的数据类型
    InfoType data;              //其他数据
} NodeType;

typedef NodeType SeqList[MAXL]; //顺序表类型

typedef struct
{
    KeyType key;            //KeyType为关键字的类型
    int link;               //指向对应块的起始下标
} IdxType;
typedef IdxType IDX[MAXI];  //索引表类型

int IdxSearch(IDX I,int m,SeqList R,int n,KeyType k)
{
    int low=0,high=m-1,mid,i;
    int b=n/m;              //b为每块的记录个数
    while (low<=high)       //在索引表中进行二分查找,找到的位置存放在low中
    {
        mid=(low+high)/2;
        if (I[mid].key>=k)
            high=mid-1;
        else
            low=mid+1;
    }
    //应在索引表的high+1块中,再在线性表中进行顺序查找
    i=I[high+1].link;
    while (i<=I[high+1].link+b-1 && R[i].key!=k) i++;
    if (i<=I[high+1].link+b-1)
        return i+1;
    else
        return 0;
}

int main()
{
    int i,n=56,m=7,j;
    SeqList R;
    IDX I= {{22,0},{45,8},{98,16},{158,24},{243,32},{492,40},{856,48}};
    KeyType a[]= {22 ,4  ,23 ,11 ,20 ,2  ,15 ,13 ,
                  30 ,45 ,26 ,34 ,29 ,35 ,26 ,36 ,
                  55 ,98 ,56 ,74 ,61 ,90 ,80 ,96 ,
                  127,158,116,114,128,113,115,102,
                  184,211,243,188,187,218,195,210,
                  279,307,492,452,408,361,421,399,
                  856,523,704,703,697,535,534,739};
    KeyType x=200;
    for (i=0; i         R[i].key=a[i];
    j=IdxSearch(I,m,R,n,x);
    if (j!=0)
        printf("%d是第%d个数据\n",x,j);
    else
        printf("未找到%d\n",x);
    return 0;
}

查找61时

查找739时

查找200时