C++ :

#include <iostream> 
using namespace std;
int main() {
	int N, M, s2[1000], s[1000];
 	while (cin >> M >> N) {
 		int s1 = 0, j = -1, k = 0, ss = 1; 
 		for (int i = 0; i < N; i++) {  //将N个英文单词存入数组s2当中 
			cin >> s2[i];
		}
 		for (int c = 0; c < N; c++) {  //翻译N个英文单词 
	 		for (int i = k; i <= j; i++) {  //检查此次翻译的单词内存中是否有 
			 	if (s2[c] == s[i]) {
				 	ss = 0;
 					break;
				}
 			}
			if (ss) {
				s[++j] = s2[c];  //存储外存单词 
 				if(j-k+1 > M)
 					k++;  //利用k的值变化，在11行循环跳过已经被替代的单词 
 				s1++;  //外存查找次数 
			}
 			ss = 1;
		}
		cout << s1 << endl;
	}
 	return 0;   
}

Pascal :

var
  total:longint;
  j,x,w:longint;
  m1:array[1..100] of longint;
  n1:array[1..1000] of longint;
  m,n,q:longint;

function s(n:longint):boolean;
var i:longint;
begin
  for i:= 1 to x do
    if n=m1[i] then
      begin
        s:=true;
        exit;
      end;
  s:=false;
end;


begin
  fillchar(m1,sizeof(m1),0);
  fillchar(n1,sizeof(n1),0);
  read(m) ;
  readln(n);
  for w:= 1 to n-1 do
  read(n1[w]) ;
  readln(n1[n]);


  m1[1]:=n1[1];
  total:=1;
  x:=1;
  for j:=2 to n do
    if not s(n1[j]) then
      begin
        inc(total);
        if x>=m then
          begin
            for q:= 1 to x-1 do
              m1[q]:=m1[q+1];
            m1[x]:=n1[j];
          end
        else
          begin
            inc(x);
            m1[x]:=n1[j];
          end;
      end;
  writeln(total);
end.