贪心 CodeForces 137B Permutation

题目传送门

 /*
     贪心：因为可以任意修改，所以答案是没有出现过的数字的个数
 */
 #include <cstdio>
 #include <algorithm>
 #include <cstring>
 using namespace std;

 const int MAXN = 5e3 + ;
 const int INF = 0x3f3f3f3f;
 int a[MAXN];
 bool vis[MAXN];

 int main(void)        //CodeForces 137B Permutation
 {
     int n;
     while (scanf ("%d", &n) == )
     {
         memset (vis, false, sizeof (vis));
         for (int i=; i<=n; ++i)
         {
             scanf ("%d", &a[i]);
             vis[a[i]] = true;
         }
         int cnt = ;
         for (int i=; i<=n; ++i)
         {
             if (!vis[i])    cnt++;
         }
         printf ("%d\n", cnt);
     }

     return ;
 }