2017.11.26【清华集训2017】模拟

 1 #include
 2 #include
 3 #include
 4 #include
 5 #define fo(i,a,b) for(int i=a;i<=b;i++)
 6 #define fd(i,a,b) for(int i=a;i>=b;i--)
 7 #define fh(i,x) for(int i=head[x];i;i=next[i])
 8 typedef long long LL;
 9 using namespace std;
10 inline int max(int x,int y) {return (xy:x;}
11 inline int min(int x,int y) {return (xx:y;}
12 inline int read() {
13     int x=0,f=1;char ch=getchar();
14     while(ch<'0'||ch>'9') f=(ch=='-')?-1:f,ch=getchar();
15     while(ch>='0'&&ch<='9') x=x*10+(ch-'0'),ch=getchar();return f*x;
16 }
17 const int N=1e3+100;
18 struct node {
19     int _lca,v;
20     node() {}
21     node(int a,int b):_lca(a),v(b) {}
22 };
23 struct node1 {
24     int val,u,v,_lca;
25     node1() {}
26     node1(int _val,int _u,int _v,int l):val(_val),u(_u),v(_v),_lca(l){}
27 }to1[N*N],g[N*N];
28 int to[N],w[N],next[N],head[N],tot,cnt,mx;
29 int tot1,next1[N*N],head1[N*N],fa[N],ans;
30 int dep[N],go[N][20],gw[N][20],n,x;
31 void add(int x,int y,int ww) {to[++tot]=y,w[tot]=ww,next[tot]=head[x],head[x]=tot;}
32 void add1(int val,int u,int v,int _lca) {to1[++tot1]=node1(val,u,v,_lca),next1[tot1]=head1[val],head1[val]=tot1;}
33 void dfs(int x) {
34     fh(i,x) {
35         dep[to[i]]=dep[x]+1,go[to[i]][0]=x,gw[to[i]][0]=w[i];
36         dfs(to[i]);
37     }
38 }
39 void init_lca() {
40     dep[0]=1,dfs(0);
41     fo(i,1,17) fo(j,0,n-1) go[j][i]=go[go[j][i-1]][i-1],gw[j][i]=gw[j][i-1]^gw[go[j][i-1]][i-1];
42 }
43 node lca(int a,int b) {
44     if(dep[a]>dep[b]) swap(a,b);
45     int f=dep[b]-dep[a],z=0;
46     fo(i,0,17) if(f&(1<go[b][i];
47     if(a==b) return node(a,z);
48     fo(i,0,17) {
49         if(go[a][i]!=go[b][i]) z^=gw[a][i]^gw[b][i],a=go[a][i],b=go[b][i];
50     }
51     return node(go[a][0],z^gw[a][0]^gw[b][0]);
52 }
53 int main() {
54     n=read();
55     fo(i,1,n-1) fa[i]=read();
56     fo(i,1,n-1) x=read(),add(fa[i],i,x);
57     init_lca();
58     fo(i,0,n-1) {
59         fo(j,i+1,n-1) {
60             node tmp=lca(i,j);
61             add1(tmp.v,i,j,tmp._lca);
62             g[++cnt]=node1(tmp.v,i,j,tmp._lca);
63             mx=max(mx,tmp.v);
64         }
65     }
66     fd(i,2048,mx) {
67         fo(j,1,cnt) {
68             if(!head1[i^g[j].val])continue;
69             else {
70                     printf("%d\n",i);return 0;
71             }
72         }
73     }
74     printf("%d\n",max(mx,ans));
75     return 0;
76 }

 1 #include
 2 #include
 3 #include
 4 #include
 5 #define fo(i,a,b) for(int i=a;i<=b;i++)
 6 #define fd(i,a,b) for(int i=a;i>=b;i--)
 7 #define fh(i,x) for(int i=head[x];i;i=next[i])
 8 typedef long long LL;
 9 using namespace std;
10 inline int max(int x,int y) {return (xy:x;}
11 inline int min(int x,int y) {return (xx:y;}
12 inline int read() {
13     int x=0,f=1;char ch=getchar();
14     while(ch<'0'||ch>'9') f=(ch=='-')?-1:f,ch=getchar();
15     while(ch>='0'&&ch<='9') x=x*10+(ch-'0'),ch=getchar();return f*x;
16 }
17 const int N=1e3+50;
18 int f[N],g[N],val[N],n,fa[N];
19 int to[N],next[N],head[N],tot;
20 void add(int x,int y) {to[++tot]=y,next[tot]=head[x],head[x]=tot;}
21 void dfs(int x) {
22     f[x]=val[x];
23     fh(i,x) dfs(to[i]);
24     fh(i,x) f[x]+=max(f[to[i]],0);
25 }
26 void dp(int x) {
27     fh(i,x) dp(to[i]);
28     fh(i,x) g[x]+=max(f[to[i]],g[to[i]]);
29 }
30 int main() {
31     n=read();
32     fo(i,1,n-1) fa[i]=read(),add(fa[i],i);
33     fo(i,0,n-1) val[i]=read();
34     dfs(0),dp(0);
35     printf("%d\n",max(f[0],g[0]));
36     return 0;
37 }

 1 #include
 2 #include
 3 #include
 4 #include
 5 #define fo(i,a,b) for(int i=a;i<=b;i++)
 6 #define fd(i,a,b) for(int i=a;i>=b;i--)
 7 #define fh(i,x) for(int i=head[x];i;i=next[i])
 8 typedef long long LL;
 9 using namespace std;
10 inline int max(int x,int y) {return (xy:x;}
11 inline int min(int x,int y) {return (xx:y;}
12 inline int read() {
13     int x=0,f=1;char ch=getchar();
14     while(ch<'0'||ch>'9') f=(ch=='-')?-1:f,ch=getchar();
15     while(ch>='0'&&ch<='9') x=x*10+(ch-'0'),ch=getchar();return f*x;
16 }
17 const int N=1e5+50,inf=0x3f3f3f3f;
18 char s[N];
19 int g[N][27],b[27],cnt[N][27],f[N][27],l,r,n,m,now;
20 int main() {
21     //freopen("c.in","r",stdin),freopen("c.out","w",stdout);
22     n=read(),m=read();
23     scanf("%s",s+1);
24     fo(i,1,n) cnt[i][s[i]-'a']++;
25     fo(j,0,25) fo(i,1,n) cnt[i][j]+=cnt[i-1][j];
26     fo(j,1,26) g[0][j]=1;
27     fo(i,1,n) {
28         int t=s[i]-'a';
29         fo(j,1,26) b[j]=n+1;
30         fo(j,1,26) {
31             if(cnt[i-1][t]-cnt[g[i-1][j]-1][t]==0) b[j+1]=min(b[j+1],g[i-1][j]);
32             else b[j]=min(b[j],g[i-1][j]);
33         }
34         b[1]=min(b[1],i);
35         fo(j,1,26) g[i][j]=b[j];
36     }
37     fo(i,0,27) f[1][i]=1;
38     fo(i,2,n) {
39         fo(j,0,26) f[i][j]=n+1;
40         fo(j,0,26) {
41             fo(t,1,26) {
42                 l=g[i][t],l--;
43                 (t==1)?r=i:r=g[i][t-1];
44                 r--;
45                 fo(st,0,j+1-t) f[i][j]=min(f[i][j],f[l][st]+1);
46             }
47         }
48         if(i1,26) f[i][j]=min(f[i][j],f[i][j-1]);
49     }
50     fd(j,26,0) {
51         if(f[n][j]<=m) now=j;
52         else break;
53     }
54     printf("%d\n",m+now);
55 }