顺序查找

int search_seq(int *A,int len,int key){
    A[0] = key;    //"哨兵"
    for(i=len;A[i]!=key;--i);
    return i;
}

二分查找

版本一：

int bin_search(){
    int low=0;high=L.len-1,mid;
    while(low<=high){
        mid=(low+high)/2;
        if(L.elem[mid]==key)
            return mid;
        else if(L.elem[mid]>key)
            high=mid-1;
        else
            low=mid+1;
    }
    return -1;
}

版本二：

//二分查找
int vector_bin_search(struct vector v,int e,int lo,int hi)
{
    while (lo<hi) {
        int mi = (lo+hi)>>1;
        
        if(e<*(v.elem+mi)){
            hi = mi;
        }else{
            lo = mi + 1;
        }
    }
    
    return --lo;
}

分块查找

最理想的块长为