bzoj4199: [Noi2015]品酒大会

题面见http://uoj.ac/problem/131

一道后缀数组题

先求出height，然后从大到小枚举每个height。

然后对于每个

 1 #include<cstdio>
 2 #include<iostream>
 3 #include<cmath>
 4 #include<cstring>
 5 #include<algorithm>
 6 #define maxn 300005
 7 #define inf 1LL<<62
 8 using namespace std;
 9 typedef long long int64;
10 char ch,s[maxn];
11 int n,val[maxn];
12 int64 ans[2][maxn];
13 int fa[maxn],siz[maxn],list[maxn],max_val[maxn],min_val[maxn];
14 int SA[maxn],rank[maxn],height[maxn],sum[maxn],t1[maxn],t2[maxn];
15 bool cmp(int x,int y){
16     if (height[x]!=height[y]) return height[x]>height[y];
17     return x<y;
18 }
19 bool ok;
20 void read(int &x){
21     for (ok=0,ch=getchar();!isdigit(ch);ch=getchar()) if (ch=='-') ok=1;
22     for (x=0;isdigit(ch);x=x*10+ch-'0',ch=getchar());
23     if (ok) x=-x;
24 }
25 void get_SA(){
26     int *x=t1,*y=t2,m=255,tot=0;
27     for (int i=1;i<=n;i++) sum[x[i]=s[i]]++;
28     for (int i=1;i<=m;i++) sum[i]+=sum[i-1];
29     for (int i=n;i>=1;i--) SA[sum[x[i]]--]=i;
30     for (int len=1;tot<n;len<<=1,m=tot){
31         tot=0;
32         for (int i=n-len+1;i<=n;i++) y[++tot]=i;
33         for (int i=1;i<=n;i++) if (SA[i]>len) y[++tot]=SA[i]-len;    
34         for (int i=1;i<=m;i++) sum[i]=0;
35         for (int i=1;i<=n;i++) sum[x[y[i]]]++;
36         for (int i=1;i<=m;i++) sum[i]+=sum[i-1];
37         for (int i=n;i>=1;i--) SA[sum[x[y[i]]]--]=y[i];
38         swap(x,y),x[SA[1]]=tot=1;
39         for (int i=2;i<=n;i++){
40             if (y[SA[i]]!=y[SA[i-1]]||y[SA[i]+len]!=y[SA[i-1]+len]) tot++;
41             x[SA[i]]=tot;    
42         }
43     }
44     for (int i=1;i<=n;i++) rank[i]=x[i];
45 }
46 void get_height(){
47     for (int i=1,j=0;i<=n;i++){
48         if (rank[i]==1) continue;
49         while (s[i+j]==s[SA[rank[i]-1]+j]) j++;
50         height[rank[i]]=j;
51         if (j>0) j--;
52     }    
53 }
54 int find(int x){return fa[x]==x?x:fa[x]=find(fa[x]);}
55 void merge(int x,int y){
56     siz[y]+=siz[x];
57     max_val[y]=max(max_val[y],max_val[x]);
58     min_val[y]=min(min_val[y],min_val[x]);
59     fa[x]=y;    
60 }
61 int main(){
62     read(n);
63     scanf("%s",s+1);
64     get_SA(),get_height();
65     for (int i=1;i<=n;i++) read(val[i]);
66     for (int i=1;i<=n;i++) max_val[i]=val[SA[i]];
67     for (int i=1;i<=n;i++) min_val[i]=val[SA[i]];
68     for (int i=1;i<=n;i++) fa[i]=i;
69     for (int i=1;i<=n;i++) siz[i]=1;
70     for (int i=1;i<n;i++) list[i]=i+1;
71     for (int i=1;i<=n;i++) ans[1][i]=-inf;
72     sort(list+1,list+n,cmp);
73     for (int i=1;i<n;i++){
74         int x=find(list[i]-1),y=find(list[i]);
75         ans[0][height[list[i]]]+=1LL*siz[x]*siz[y];
76         ans[1][height[list[i]]]=max(ans[1][height[list[i]]],1LL*max_val[x]*max_val[y]);
77         ans[1][height[list[i]]]=max(ans[1][height[list[i]]],1LL*max_val[x]*min_val[y]);
78         ans[1][height[list[i]]]=max(ans[1][height[list[i]]],1LL*min_val[x]*max_val[y]);
79         ans[1][height[list[i]]]=max(ans[1][height[list[i]]],1LL*min_val[x]*min_val[y]);
80         merge(x,y);
81     }
82     for (int i=n-2;i>=0;i--) ans[0][i]+=ans[0][i+1],ans[1][i]=max(ans[1][i],ans[1][i+1]);
83     for (int i=0;i<n;i++) printf("%lld %lld\n",ans[0][i],ans[0][i]?ans[1][i]:0);
84     return 0;
85 }