BZOJ1049: [HAOI2006]数字序列

 1 #include<cstdio>
 2 #include<cstdlib>
 3 #include<cmath>
 4 #include<cstring>
 5 #include<algorithm>
 6 #include<iostream>
 7 #include<vector>
 8 #include<map>
 9 #include<set>
10 #include<queue>
11 #include<string>
12 #define inf 1000000000
13 #define maxn 50000+5
14 #define maxm 100000+5
15 #define eps 1e-10
16 #define ll long long
17 #define pa pair<int,int>
18 #define for0(i,n) for(int i=0;i<=(n);i++)
19 #define for1(i,n) for(int i=1;i<=(n);i++)
20 #define for2(i,x,y) for(int i=(x);i<=(y);i++)
21 #define for3(i,x,y) for(int i=(x);i>=(y);i--)
22 #define for4(i,x) for(int i=head[x],y=e[i].go;i;i=e[i].next,y=e[i].go)
23 #define mod 1000000007
24 using namespace std;
25 inline int read()
26 {
27     int x=0,f=1;char ch=getchar();
28     while(ch<‘0‘||ch>‘9‘){if(ch==‘-‘)f=-1;ch=getchar();}
29     while(ch>=‘0‘&&ch<=‘9‘){x=10*x+ch-‘0‘;ch=getchar();}
30     return x*f;
31 }
32 int n,a[maxn],b[maxn],f[maxn],next[maxn],last[maxn];
33 ll g[maxn],t[maxn];
34 int main()
35 {
36     freopen("input.txt","r",stdin);
37     freopen("output.txt","w",stdout);
38     n=read();
39     for1(i,n+2)b[i]=inf;
40     for2(i,2,n+1)a[i]=read()-i;
41     a[1]=-inf;a[n+2]=inf-1;
42     n+=2;
43     for1(i,n)
44     {
45         f[i]=upper_bound(b+1,b+n+1,a[i])-b;
46         b[f[i]]=a[i];
47     }
48     cout<<n-f[n]<<endl;
49     for3(i,n,1)next[i]=last[f[i]],last[f[i]]=i;
50     memset(g,127,sizeof(g));
51     for1(i,n)
52     {
53         if(f[i]==1){g[i]=0;continue;}
54         t[i]=0;
55         for3(j,i-1,last[f[i]-1])t[j]=t[j+1]+abs(a[j]-a[i]);
56         for(int j=last[f[i]-1];j;j=next[j])if(a[j]<=a[i])
57         {
58             if(j+1==i){g[i]=min(g[i],g[j]);continue;}
59             ll tot=0;
60             for2(k,j,i-1)
61             {
62                 tot+=abs(a[j]-a[k]);
63                 g[i]=min(g[i],g[j]+tot+t[k+1]);
64             }
65         }
66     }
67     cout<<g[n]<<endl;
68     return 0;
69 }