wordpress同步到本地,外贸网站seo教程,手机网站大全12345,网站建设 java水题。题目大意为输入一个p,n,再输入n组数据,每组数据对p取余,当和前面相同时,发现冲突,记下第几组,找到最后一组没有找到和前面一样的输出-1。
*可以采用一个标记数组,就变得很简单了。 A. DZ…
DZY has a hash table with p buckets, numbered from 0 to p - 1. He wants to insert n numbers, in the order they are given, into the hash table. For the i-th number xi, DZY will put it into the bucket numbered h(xi), where h(x) is the hash function. In this problem we will assume, that h(x) = x mod p. Operation a mod b denotes taking a remainder after division a by b.
However, each bucket can contain no more than one element. If DZY wants to insert an number into a bucket which is already filled, we say a "conflict" happens. Suppose the first conflict happens right after the i-th insertion, you should output i. If no conflict happens, just output -1.
Input
The first line contains two integers, p and n(2 ≤ p, n ≤ 300). Then n lines follow. The i-th of them contains an integer xi(0 ≤ xi ≤ 109).
Output
Output a single integer — the answer to the problem.