HDU 4398 Template Library Management

 1 #include <iostream>
 2 #include <cstdio>
 3 #include <cstring>
 4 #include <cstdlib>
 5 #include <cmath>
 6 #include <algorithm>
 7 #include <string>
 8 #include <queue>
 9 #include <stack>
10 #include <vector>
11 #include <map>
12 #include <set>
13 #include <functional>
14 #include <time.h>
15 
16 using namespace std;
17 
18 typedef pair<int, int> PII;
19 
20 const int INF = 1<<30;
21 const int MAXN = (int) 1e5+11;
22 
23 priority_queue<PII> q;
24 int Ti[MAXN], next[MAXN];
25 int Find[MAXN], len; //离散化用
26 int vis[MAXN]; //计算下一次出现用
27 bool inq[MAXN]; //判断是否拥有
28 int N, M;
29 
30 void input() {
31     for (int i = 0; i < N; i++)
32         scanf("%d", &Ti[i]);
33 }
34 
35 void solve() {
36     //离散化
37     for (int i = 0; i < N; i++)
38         Find[i] = Ti[i];
39     sort(Find, Find+N);
40     len = unique(Find, Find+N) - Find;
41     for (int i = 0; i < N; i++)
42         Ti[i] = lower_bound(Find, Find+len, Ti[i]) - Find;
43 
44     //计算next[]
45     for (int i = 0; i <= len; i++) vis[i] = N+1; //初始化vis[]
46     for (int i = N-1; i >= 0; i--) {
47         next[i] = vis[Ti[i]];
48         vis[Ti[i]] = i;
49     }
50 
51     int ans = 0, have = 0;
52     while (!q.empty()) q.pop(); //初始化队列
53     memset(inq, false, sizeof(inq));
54     for (int i = 0, j = 0; i < M; i++) { //一开始就有的模板
55         int t = Find[j]==(i+1) ? j++ : len;
56         q.push(make_pair(vis[t], t));
57         inq[t] = true;
58         have++;
59     }
60 
61     for (int i = 0; i < N; i++) {
62         if (!inq[Ti[i]]) { //如果现在没有有这个模板，那么就要去借
63             have++;
64             ans++;
65         }
66         //把那个模板拿过来
67         inq[Ti[i]] = true;
68         q.push(make_pair(next[i], Ti[i]));
69 
70         if (have>M) { //需要丢弃模板
71             PII x = q.top(); q.pop();
72             inq[x.second] = false;
73             have--;
74         }
75     }
76 
77     printf("%d\n", ans);
78 }
79 
80 int main() {
81     #ifdef Phantom01
82         freopen("I.txt", "r", stdin);
83     #endif //Phantom01
84 
85     while (scanf("%d%d", &N, &M)!=EOF) {
86         input();
87         solve();
88     }
89 
90     return 0;
91 }