5.21排序与检索

样例输入：
4 1//输入四块大理石，提一个问题
2 3 5 1//输入的大理石
5//问5在那一块大理石上
5 2
1 3 3 31
2 3

样例输出:
CASE# 1:
5 found at 4//4是按照升序排好之后的序号
CASE# 2:
2 not found
3 found at 3

#include<cstdio>
#include<algorithm>
using namespace std;
const int maxn = 10000;
int main()
{
    int n, q, x, a[maxn],kcase = 0;
    while (scanf("%d%d", &n, &q) == 2 && n)//输入有效的两个数，并且n要大于零
    {
        printf("CASE# %d:\n",++kcase);
        for (int i = 0; i < n; i++)
        {
            scanf("%d", &a[i]);
        }
        sort(a, a + n);//排序
        while (q > 0)
        {
            scanf("%d",&x);
            int p = lower_bound(a, a + n, x) - a;//按照升序排列a到a+n之间的数，排好之后返回一个地址
            if (a[p] == x)
            {
                printf("%d found at %d\n", x, p + 1);
            }
            else
            {
                printf("%d not found\n", x);
            }
        }
    }

    return 0;
}