BZOJ1826: [JSOI2010]缓存交换

 1 #include <iostream>
 2 #include <cstdio>
 3 #include <cstdlib>
 4 #include <cstring>
 5 #include <algorithm> 
 6 #include <map>
 7 #include <queue>
 8 #define max(a, b) ((a) > (b) ? (a) : (b)) 
 9 #define min(a, b) ((a) < (b) ? (a) : (b))
10 
11 inline void read(long long &x)
12 {
13     x = 0;char ch = getchar(), c = ch;
14     while(ch < ‘0‘ || ch > ‘9‘)c = ch, ch = getchar();
15     while(ch <= ‘9‘ && ch >= ‘0‘)x = x * 10 + ch - ‘0‘, ch = getchar();
16     if(c == ‘-‘)x = -x;
17 }
18 
19 const long long MAXN = 100000 + 10;
20 
21 long long n,m,num[MAXN],cnt[MAXN],nxt[MAXN],ans,chuxian[MAXN],sum;
22 
23 bool cmp(long long a, long long b)
24 {
25     return num[a] < num[b];
26 }
27 
28 struct cmpp
29 {
30     bool operator()(long long a, long long b)
31     {
32         return nxt[a] < nxt[b];
33     }
34 };
35 
36 std::priority_queue <int, std::vector<int>, cmpp> q;
37 
38 int main()
39 {
40     read(n), read(m);
41     for(register long long i = 1;i <= n;++ i)
42         read(num[i]), cnt[i] = i;
43     std::sort(cnt + 1, cnt + 1 + n, cmp);
44     long long tot = 1, pre = num[cnt[1]];
45     num[cnt[1]] = tot;
46     for(register long long i = 2;i <= n;++ i)
47         if(num[cnt[i]] == pre)num[cnt[i]] = tot;
48         else ++ tot, pre = num[cnt[i]], num[cnt[i]] = tot;
49     memset(cnt, 0, sizeof(cnt));
50     memset(nxt, 0x3f, sizeof(nxt));
51     for(register long long i = n;i >= 1;-- i)
52     {
53         if(cnt[num[i]])nxt[i] = cnt[num[i]];
54         cnt[num[i]] = i;
55     }
56     memset(cnt, 0, sizeof(cnt));
57     
58     ///cnt[i]表示i这个数是否在堆中以及i在原数组中的位置，chuxian[i]表示原数组i元素是否在堆中 
59     for(register long long i = 1;i <= n;++ i)
60     {
61         if(cnt[num[i]])
62         {
63             q.push(i);
64             chuxian[cnt[num[i]]] = 0;
65             chuxian[i] = 1; 
66         }
67         else
68         {
69             if(sum < m)q.push(i), cnt[num[i]] = i, chuxian[i] = 1, ++ans, ++sum;
70             else
71             {
72                 while(chuxian[q.top()] == 0)q.pop();
73                 cnt[num[q.top()]] = 0;
74                 chuxian[q.top()] = 0;
75                 q.pop();
76                 q.push(i);
77                 chuxian[i] = 1;
78                 cnt[num[i]] = i;
79                 ++ ans;
80             }
81         }
82     }
83     printf("%lld", ans);
84     return 0;
85 }