数据结构实验五：查找

查找——实现监视哨法查找

#include<stdio.h>
#include<stdlib.h>
int cmp(const void *a,const void *b)
{
    return *(int *)a-*(int *)b;
}
int main()
{
    int a[101],i;
    for(i=1;i<=100;i++)
        a[i]=rand()%100;
    for(i=1;i<=100;i++)
        printf("%d ",a[i]);
    printf("\n");
    int key;
    scanf("%d",&key);
    printf("顺序查找\n");
    a[0]=key;
    for(i=100;i>=0;i--)
        if(a[i]==key){
                printf("%d\n",i);
                break;
                }
    qsort(&a[1],100,sizeof(int),cmp);
    for(i=1;i<=100;i++)
        printf("%d ",a[i]);
    printf("\n");
    printf("折半查找\n");
    int mid,start=1,end=100;
    mid=(start+end)/2;
    while(start<=end)
    {
        if(a[mid]==key){
            printf("%d\n",mid);
            break;
        }
        if(a[mid]>key){
            end=mid-1;
            mid=(end+start)/2;
        }
        else{
            start=mid+1;
            mid=(start+end)/2;
        }
    }
    printf("end\n");
}