求助P1540 [NOIP2010 提高组] 机器翻译

#include<bits/stdc++.h>
using namespace std;
queue<int> q;
int m,n;
int x;
int tot;
int a[1010];
inline int read()
{
	register int x=0,y=1;
	register char c=getchar();
	while (c<'0'||c>'9')
	{
		if (c=='-')
		{
			y=-1;
		}
		c=getchar();
	}
	while (c>='0'&&c<='9')
	{
		x=x*10+c-'0';
		c=getchar();
	}
	return x*y;
}
int main()
{
	m=read();
	n=read();
	for (int i=1;i<=n;i++)
	{
		x=read();
		int t=q.size();
		if (a[x]==0)
		{
			a[x]=x;
		}
		else if (a[x]!=0) continue;
		if (t>=0&&t<m)
		{
			q.push(x);
			tot++;
		}
		else
		{
			a[q.front()]=0;
			q.pop();
			q.push(x);
			tot++;
		}
	}
	cout<<tot;
	return 0;
}