BZOJ1528 [POI2005]sam-Toy Cars

 1 /**************************************************************
 2     Problem: 1528
 3     User: rausen
 4     Language: C++
 5     Result: Accepted
 6     Time:716 ms
 7     Memory:13304 kb
 8 ****************************************************************/
 9  
10 #include <cstdio>
11 #include <queue>
12 #include <utility>
13  
14 using namespace std;
15 const int N = 500005;
16  
17 int n, k, p, ans;
18 int a[N], next[N], last[N];
19 bool v[N];
20 priority_queue <pair <int, int> > h;
21  
22 int main() {
23     int i;
24     scanf("%d%d%d", &n, &k, &p);
25     for (i = 1; i <= n; ++i)
26         last[i] = p + 1;
27     for (i = 1; i <= p; ++i)
28         scanf("%d", a + i);
29     for (i = p; i; --i) {
30         next[i] = last[a[i]];
31         last[a[i]] = i;
32     }
33     for (i = 1; i <= p; ++i) {
34         if (v[a[i]])
35             h.push(make_pair(next[i], a[i])); else
36         if (k) {
37             h.push(make_pair(next[i], a[i]));
38             v[a[i]] = 1, --k, ++ans;
39         } else {
40             while (!v[h.top().second]) h.pop();
41             v[h.top().second] = 0, h.pop();
42             h.push(make_pair(next[i], a[i]));
43             v[a[i]] = 1, ++ans;
44         }
45     }
46     printf("%d\n", ans);
47     return 0;
48 }