POJ1836Alignment（LCA）

 1 #include <iostream>
 2 #include <cstdio>
 3 #include <algorithm>
 4 #include <cstring>
 5 using namespace std;
 6 const int MAX = 1000 + 10;
 7 const double F = 10e-6;
 8 double heigh[MAX];
 9 int dp1[MAX],dp2[MAX];
10 void LCA(int n)
11 {
12     memset(dp1, 0, sizeof(dp1));
13     dp1[1] = 1;
14     for(int i = 1; i <= n; i++)
15     {
16         int maxn = 0;
17         for(int j = i - 1; j > 0; j--)
18         {
19             if(heigh[i] > heigh[j])
20             {
21                 maxn = max(maxn,dp1[j]);
22             }
23         }
24         dp1[i] = max(dp1[i], maxn + 1);
25     }
26 }
27 void LDA(int n)
28 {
29     memset(dp2, 0, sizeof(dp2));
30     dp2[n] = 1;
31     for(int i = n; i > 0; i--)
32     {
33         int maxn = 0;
34         for(int j = i + 1; j <= n; j++)
35         {
36             if(heigh[i] > heigh[j])
37             {
38                 maxn = max(maxn, dp2[j]);
39             }
40         }
41         dp2[i] = max(dp2[i], maxn + 1);
42     }
43 }
44 int Cout(int n)
45 {
46     int maxn = 0;
47     for(int i = 1; i <= n; i++)
48     {
49         int temp = 0;
50         for(int j = i + 1; j <= n; j++)
51         {
52             if(heigh[i] >= heigh[j])
53                 temp = max(temp, dp2[j]);
54         }
55         maxn = max(maxn, dp1[i] + temp);
56     }
57     return n - maxn;
58 }
59 int main()
60 {
61     int n;
62     while(scanf("%d", &n) != EOF)
63     {
64         for(int i = 1; i <= n; i++)
65         {
66             scanf("%lf", &heigh[i]);
67         }
68         LCA(n);
69         LDA(n);
70         printf("%d\n",Cout(n));
71     }
72     return 0;
73 }