https://files.cnblogs.com/files/Winniechen/usaco2012-2013.pdf
做的不是很好，还请见谅！
如果有什么疑问，可以QQ上找我。
QQ号：1967199892
附上代码：
BZOJ3010: [Usaco2012 Dec]Gangs of Istanbull
#include <cstdio>
#include <cmath>
#include <algorithm>
#include <iostream>
#include <queue>
#include <cstdlib>
#include <cstring>
using namespace std;
#define N 105
void Update(int& gang,int& cows,int come)
{
if(!cows)gang=come;
if(gang==come)cows++;
else cows--;
}
int n,m;vector<int > v;
int max_cow(int gang,int cows,vector <int>v)
{
sort(v.begin()+1,v.end());
while(v.back()>0)
{
for(int i=v.size()-1;i;i--)
{
Update(gang,cows,i);
v[i]--;
if(v[i-1]<=v[i])break;
}
}
for(int i=0;i<v[0];i++)Update(gang,cows,0);
return gang==0?cows:0;
}
int main()
{
int n,m;
scanf("%d%d",&n,&m);
for(int i=0;i<m;i++)
{
int x;
scanf("%d",&x);
v.push_back(x);
}
int gang=0,cow=0,ret=max_cow(gang,cow,v);
if(ret>0)
{
printf("YES\n%d\n",ret);
for(int i=0;i<n;i++)
{
int pre_gang=gang,pre_cow=cow;
for(int j=0;;j++)
{
if(!v[j])continue;
v[j]--;
Update(gang,cow,j);
if(max_cow(gang,cow,v)==ret){printf("%d\n",j+1);break;}
v[j]++;
gang=pre_gang;cow=pre_cow;
}
}
}else
{
printf("NO\n");
}
return 0;
}
BZOJ3011: [Usaco2012 Dec]Running Away From the Barn
#include <cstdio>
#include <algorithm>
#include <iostream>
#include <queue>
#include <cmath>
#include <cstring>
#include <cstdlib>
using namespace std;
#define N 200005
#define ll long long
struct node
{
int dis,ls,rs;
ll x;
}mp[N];
struct no
{
int to,next;
ll val;
}e[N];
int head[N],cnt;
void add(int x,int y,ll z)
{
e[cnt].to=y;
e[cnt].val=z;
e[cnt].next=head[x];
head[x]=cnt++;
return ;
}
int fa[N],n,siz[N];
ll dep[N],L;
int merge(int x,int y)
{
if(!x)return y;
if(!y)return x;
if(mp[x].x<mp[y].x)swap(x,y);
mp[x].rs=merge(mp[x].rs,y);
if(mp[mp[x].rs].dis>mp[mp[x].ls].dis)swap(mp[x].ls,mp[x].rs);
mp[x].dis=mp[mp[x].rs].dis+1;
return x;
}
int find(int x)
{
if(x==fa[x])return x;
return fa[x]=find(fa[x]);
}
void dfs(int x,int from)
{
siz[x]=1;
for(int i=head[x];i!=-1;i=e[i].next)
{
int to1=e[i].to;
if(to1!=from)
{
mp[to1].x=dep[to1]=dep[x]+e[i].val;
dfs(to1,x);
siz[x]+=siz[to1];
int fx=find(x),fy=find(to1);
fa[fx]=fa[fy]=merge(fx,fy);
}
}
int fx=find(x);
while(mp[fx].x>L+dep[x])
{
fa[fx]=fa[mp[fx].ls]=fa[mp[fx].rs]=merge(mp[fx].ls,mp[fx].rs);
siz[x]--;
fx=find(x);
}
return ;
}
int main()
{
fa[1]=1;
memset(head,-1,sizeof(head));
scanf("%d%lld",&n,&L);
for(int i=2;i<=n;i++)
{
fa[i]=i;
int x;
ll y;
scanf("%d%lld",&x,&y);
add(x,i,y);
}
dfs(1,0);
for(int i=1;i<=n;i++)
{
printf("%d\n",siz[i]);
}
return 0;
}
BZOJ3012: [Usaco2012 Dec]First!
#include <cstdio>
#include <algorithm>
#include <queue>
#include <cstring>
#include <cstdlib>
#include <cmath>
#include <iostream>
#include <set>
#include <vector>
using namespace std;
#define N 30005
struct node
{
int son[27],flag;
}a[N*10];
struct no
{
int to,next;
}e[N];
int head[30],cnt,ans[N],in1[N],tot=1,n;
char s[N][305];
void add(int x,int y)
{
e[cnt].to=y;
e[cnt].next=head[x];
head[x]=cnt++;
in1[y]++;
}
void insert(int x)
{
int rt=1;
int len=strlen(s[x]);
for(int i=0;i<len;i++)
{
int idx=s[x][i]-'a'+1;
if(!a[rt].son[idx])a[rt].son[idx]=++tot;
rt=a[rt].son[idx];
}
a[rt].flag=1;
}
bool tsort()
{
queue <int>q;
for(int i=1;i<=26;i++)if(!in1[i])q.push(i);
while(!q.empty())
{
int x=q.front();q.pop();
for(int i=head[x];i!=-1;i=e[i].next)
{
int to1=e[i].to;
in1[to1]--;
if(!in1[to1])q.push(to1);
}
}
for(int i=1;i<=26;i++)if(in1[i])return 0;
return 1;
}
bool check(int x)
{
int rt=1;
int len=strlen(s[x]);
for(int i=0;i<len;i++)
{
if(a[rt].flag)return 0;
int idx=s[x][i]-'a'+1;
for(int j=1;j<=26;j++)
{
if(j!=idx&&a[rt].son[j])add(idx,j);
}
rt=a[rt].son[idx];
}
return tsort();
}
int main()
{
scanf("%d",&n);
for(int i=1;i<=n;i++)
{
scanf("%s",&s[i]);
insert(i);
}
for(int i=1;i<=n;i++)
{
memset(head,-1,sizeof(head));
memset(in1,0,sizeof(in1));cnt=0;
if(!check(i))continue;
ans[++ans[0]]=i;
}
printf("%d\n",ans[0]);
for(int i=1;i<=ans[0];i++)
{
printf("%s\n",s[ans[i]]);
}
return 0;
}
BZOJ3013: [Usaco2012 Nov]Balanced Cow Breeds
#include <cstdio>
#include <cmath>
#include <algorithm>
#include <iostream>
#include <queue>
#include <cstdlib>
#include <cstring>
using namespace std;
#define N 1005
#define mod 2012
int f[N*2],n,sum;
char s[N];
int main()
{
scanf("%s",s+1);n=strlen(s+1);sum=f[1]=1;
for(int i=1;i<=n&&sum>0;i++)
{
int x=0;
if(s[i]=='(')x=1;else x=-1;
sum+=x;
if(x==-1)
{
for(int j=1;j<=sum;j++)
{
f[j]=(f[j-x]+f[j])%mod;
}
}else
{
for(int j=sum;j>=1;j--)
{
f[j]=(f[j-x]+f[j])%mod;
}
}
f[sum+1]=0;
}
if(sum!=1)
{
puts("0");return 0;
}
printf("%d\n",f[1]);
return 0;
}
BZOJ3014: [Usaco2012 Nov]Balanced Trees
#include <cstdio>
#include <algorithm>
#include <cmath>
#include <cstring>
#include <cstdlib>
#include <queue>
#include <iostream>
using namespace std;
#define N 40005
struct node
{
int to,next;
}e[N<<1];
int head[N],cnt,vis[N],n,ans,f[N],mf[N],g[N],mg[N];
int a[N],siz[N],mx[N],rot,sn,maxx;
void add(int x,int y)
{
e[cnt].to=y;
e[cnt].next=head[x];
head[x]=cnt++;
}
void get_root(int x,int from)
{
siz[x]=1,mx[x]=0;
for(int i=head[x];i!=-1;i=e[i].next)
{
int to1=e[i].to;
if(to1!=from&&!vis[to1])
{
get_root(to1,x);
siz[x]+=siz[to1];
mx[x]=max(mx[x],siz[to1]);
}
}
mx[x]=max(sn-siz[x],mx[x]);
if(mx[x]<mx[rot])rot=x;
}
void get_left(int x,int from,int now,int last,int sum)
{
siz[x]=1;
if(now||a[x]==-1)now-=a[x];else last++;sum=max(sum,now-last);
if(!now)f[last]=1,mf[last]=max(mf[last],sum),maxx=max(last,maxx);
for(int i=head[x];i!=-1;i=e[i].next)
{
int to1=e[i].to;
if(to1!=from&&!vis[to1])
{
siz[x]+=siz[to1];
get_left(to1,x,now,last,sum);
}
}
}
void get_right(int x,int from,int now,int last,int sum)
{
siz[x]=1;
if(now||a[x]==1)now+=a[x];else last++;sum=max(sum,now-last);
if(!now)g[last]=1,mg[last]=max(mg[last],sum),maxx=max(last,maxx);
for(int i=head[x];i!=-1;i=e[i].next)
{
int to1=e[i].to;
if(to1!=from&&!vis[to1])
{
siz[x]+=siz[to1];
get_right(to1,x,now,last,sum);
}
}
}
int tms[N];
void calc(int x)
{
int v=0,maxn=0,tot=0;
for(int i=head[x];i!=-1;i=e[i].next)
{
f[0]=1,mf[0]=0;
maxx=0;tms[++tot]=i;
int to1=e[i].to;
if(!vis[to1])
{
get_left(to1,x,0,0,0);
for(int k=0;k<=maxx;k++)ans=max(ans,g[k]*f[k]*max(mf[k]+k,mg[k]+k));
for(int k=1;k<=maxx;k++)f[k]=0,mf[k]=0;
maxx=0;
get_right(to1,x,a[x]==1,a[x]==-1,a[x]==1),maxn=max(maxx,maxn);ans=max(ans,mg[0]);
if(a[x]==-1)g[1]=1,mg[1]=max(mg[1],1),maxx=max(maxx,1);
}
}
for(int i=0;i<=maxn;i++)g[i]=0,mg[i]=0;maxn=0;
for(int j=tot;j;j--)
{
int i=tms[j],to1=e[i].to;f[0]=1,mf[0]=0;maxx=0;
if(!vis[to1])
{
get_left(to1,x,0,0,0);
for(int k=0;k<=maxx;k++)ans=max(ans,g[k]*f[k]*max(mf[k]+k,mg[k]+k));
for(int k=1;k<=maxx;k++)f[k]=0,mf[k]=0;
maxx=0;
get_right(to1,x,a[x]==1,a[x]==-1,a[x]==1),maxn=max(maxx,maxn);ans=max(ans,mg[0]);
if(a[x]==-1)g[1]=1,mg[1]=max(mg[1],1),maxx=max(maxx,1);
}
}
for(int i=0;i<=maxn;i++)g[i]=0,mg[i]=0;maxn=0;
}
void dfs(int x)
{
//printf("%d\n",x);
//printf("%d\n",ans);
vis[x]=1;calc(x);
for(int i=head[x];i!=-1;i=e[i].next)
{
int to1=e[i].to;
if(!vis[to1])
{
rot=0,sn=siz[to1];
get_root(to1,x);
dfs(rot);
}
}
}
char s[2];
int main()
{
scanf("%d",&n);memset(head,-1,sizeof(head));
for(int i=2;i<=n;i++)
{
int x;
scanf("%d",&x);
add(x,i);add(i,x);
}
for(int i=1;i<=n;i++)
{
scanf("%s",s);
if(s[0]=='(')a[i]=1;
else a[i]=-1;
}
mx[0]=1<<30;sn=n;rot=0;get_root(1,0);dfs(rot);
printf("%d\n",ans);
}
BZOJ3015: [Usaco2012 Nov]Concurrently Balanced Strings
#include <cstdio>
#include <algorithm>
#include <cmath>
#include <cstring>
#include <cstdlib>
#include <queue>
#include <map>
#include <iostream>
using namespace std;
#define N 50005
int a[10][N],n,k,ans,R[10][N<<1];char s[N];
map<vector<int> ,pair<int ,int > >mp;
int main()
{
scanf("%d%d",&k,&n);
for(int i=0;i<k;i++)
{
scanf("%s",s);
for(int j=0;j<n;j++)
{
if(s[j]=='(')a[i][j]=1;
else a[i][j]=-1;
}
}
vector<int>L(k,n);
for(int i=0;i<k;i++)
{
for(int j=0;j<=2*n;j++)
{
R[i][j]=n;
}
R[i][n]=0;
}
mp[L]=make_pair(0,1);
for(int i=0;i<n;i++)
{
int left=0;
for(int j=0;j<k;j++)
{
if(a[j][i]==1)R[j][++L[j]]=i+1;
else L[j]--,R[j][L[j]]=min(R[j][L[j]],i+1);
left=max(left,R[j][L[j]]);
}
if(left==n)continue;
pair<int ,int >&tmp=mp[L];
if(tmp.first==left)ans+=tmp.second++;
else tmp=make_pair(left,1);
}
printf("%d\n",ans);
return 0;
}
BZOJ3048: [Usaco2013 Jan]Cow Lineup
#include <cstdio>
#include <algorithm>
#include <cmath>
#include <cstring>
#include <cstdlib>
#include <queue>
#include <iostream>
using namespace std;
#define N 100005
struct node
{
int x,rnk,idx;
}a[N];
int n,k,num[N],ans,tot;
bool cmp(const node &a,const node &b){return a.x<b.x;}
bool cmp1(const node &a,const node &b){return a.idx<b.idx;}
int main()
{
scanf("%d%d",&n,&k);
for(int i=1;i<=n;i++){scanf("%d",&a[i].x);a[i].idx=i;}sort(a+1,a+n+1,cmp);
int cnt=0;for(int i=1;i<=n;i++){if(a[i].x!=a[i-1].x)cnt++;a[i].rnk=cnt;}sort(a+1,a+n+1,cmp1);
int r=1,l=1;while(tot<=k+1&&r<=n){tot+=(!num[a[r].rnk]);num[a[r].rnk]++;ans=max(ans,num[a[r].rnk]);r++;}
for(int i=r;i<=n;i++)
{
tot+=(!num[a[i].rnk]);num[a[i].rnk]++;
while(tot>k+1)
{
num[a[l].rnk]--;
if(!num[a[l].rnk])tot--;
l++;
}
ans=max(num[a[i].rnk],ans);
}
printf("%d\n",ans);
}
BZOJ3049: [Usaco2013 Jan]Island Travels
#include <cstdio>
#include <algorithm>
#include <cmath>
#include <cstring>
#include <cstdlib>
#include <queue>
#include <iostream>
using namespace std;
#define N 55
#define M 1<<15
#define p(i,j) ((i-1)*c+j)
int f[16][M],map[N][N],dis[N*N],vis[N*N],n,r,c,head[N*N],cnt,idx[N];
struct node{int to,next,val;}e[N*N*10];
void add(int x,int y,int z){e[cnt].to=y;e[cnt].next=head[x];e[cnt].val=z;head[x]=cnt++;}
priority_queue <pair<int ,int > >q;
void Dijkstra(int S)
{
memset(vis,0,sizeof(vis));memset(dis,0x3f,sizeof(dis));
while(!q.empty())q.pop();q.push(make_pair(0,S));dis[S]=0;
while(!q.empty())
{
int x=q.top().second;q.pop();
if(vis[x])continue;
vis[x]=1;
for(int i=head[x];i!=-1;i=e[i].next)
{
int to1=e[i].to;
if(dis[to1]>dis[x]+e[i].val)
{
dis[to1]=dis[x]+e[i].val;
q.push(make_pair(-dis[to1],to1));
}
}
}
return ;
}
char s[N][N];int dx[4]={0,1,-1,0},dy[4]={1,0,0,-1};
void dfs(int x,int y,int cnt)
{
for(int i=0;i<4;++i)
{
int xx=x+dx[i];
int yy=y+dy[i];
if(xx<1||xx>r||yy<1||yy>c||s[xx][yy]!='X'||map[xx][yy])continue;
map[xx][yy]=cnt;
dfs(xx,yy,cnt);
}
}
int main()
{
memset(head,-1,sizeof(head));
scanf("%d%d",&r,&c);
for(int i=1;i<=r;i++)
{
scanf("%s",s[i]+1);
}
for(int i=1;i<=r;i++)
{
for(int j=1;j<=c;j++)
{
if(s[i][j]=='X')
{
if(!map[i][j])map[i][j]=++n,idx[n]=p(i,j),dfs(i,j,n);
}
else if(s[i][j]=='S')map[i][j]=0;
else map[i][j]=-1;
}
}
for(int i=1;i<=r;i++)
{
for(int j=1;j<=c;j++)
{
if(map[i][j]==-1)continue;
if(j!=c&&map[i][j+1]!=-1)add(p(i,j),p(i,j+1),!map[i][j+1]),add(p(i,j+1),p(i,j),!map[i][j]);
if(i!=r&&map[i+1][j]!=-1)add(p(i,j),p(i+1,j),!map[i+1][j]),add(p(i+1,j),p(i,j),!map[i][j]);
}
}
memset(map,0x3f,sizeof(map));memset(f,0x3f,sizeof(f));
for(int i=1;i<=n;i++)
{
f[i][1<<(i-1)]=0;Dijkstra(idx[i]);
for(int j=1;j<=n;j++)
{
map[i][j]=dis[idx[j]];
}
}
for(int S=1;S<(1<<n);S++)
{
for(int i=1;i<=n;i++)
{
if(!(S&(1<<i-1)))continue;
for(int j=1;j<=n;j++)
{
if(!(S&(1<<j-1)))continue;
int s=S^(1<<i-1);
f[i][S]=min(f[j][s]+map[j][i],f[i][S]);
}
}
}
int ans=1<<30;
for(int i=1;i<=n;i++)ans=min(ans,f[i][(1<<n)-1]);
printf("%d\n",ans);
return 0;
}
BZOJ3050: [Usaco2013 Jan]Seating
#include <cstdio>
#include <cmath>
#include <cstring>
#include <iostream>
#include <queue>
#include <algorithm>
using namespace std;
#define N 500005
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1
int sum[N<<2],lsum[N<<2],rsum[N<<2],cover[N<<2];
int n,Q;
void PushUp(int m,int rt)
{
lsum[rt]=lsum[rt<<1];
rsum[rt]=rsum[rt<<1|1];
if(lsum[rt]==(m-(m>>1)))lsum[rt]+=lsum[rt<<1|1];
if(rsum[rt]==(m>>1))rsum[rt]+=rsum[rt<<1];
sum[rt]=max(max(sum[rt<<1],sum[rt<<1|1]),lsum[rt<<1|1]+rsum[rt<<1]);
return ;
}
void PushDown(int l,int rt)
{
if(cover[rt]!=-1)
{
cover[rt<<1]=cover[rt<<1|1]=cover[rt];
rsum[rt<<1]=lsum[rt<<1]=sum[rt<<1]=cover[rt]*(l-(l>>1));
rsum[rt<<1|1]=lsum[rt<<1|1]=sum[rt<<1|1]=cover[rt]*(l>>1);
cover[rt]=-1;
}
return ;
}
void build(int l,int r,int rt)
{
cover[rt]=-1;
if(l==r)
{
rsum[rt]=lsum[rt]=sum[rt]=1;
return ;
}
int m=(l+r)>>1;
build(lson);
build(rson);
PushUp(r-l+1,rt);
return ;
}
void Update(int L,int R,int c,int l,int r,int rt)
{
if(L<=l&&r<=R)
{
rsum[rt]=c*(r-l+1);
lsum[rt]=c*(r-l+1);
sum[rt]=c*(r-l+1);
cover[rt]=c;
return ;
}
PushDown(r-l+1,rt);
int m=(l+r)>>1;
if(m>=L)Update(L,R,c,lson);
if(m<R)Update(L,R,c,rson);
PushUp(r-l+1,rt);
return ;
}
int query(int x,int l,int r,int rt)
{
if(l==r)return l;
PushDown(r-l+1,rt);
int m=(l+r)>>1;
if(sum[rt<<1]>=x)
{
return query(x,lson);
}else if(lsum[rt<<1|1]+rsum[rt<<1]>=x)
{
return m-rsum[rt<<1]+1;
}else
{
return query(x,rson);
}
}
int read()
{
int x=0;
char c=getchar();
while(c<'0'||c>'9')c=getchar();
while('0'<=c&&c<='9')
{
x=(x<<3)+(x<<1)+(c-'0');
c=getchar();
}
return x;
}
char s[10];
int main()
{
n=read(),Q=read();
build(1,n,1);
int ans=0;
while(Q--)
{
int x,y;
scanf("%s",s);
x=read();
if(s[0]=='A')
{
if(sum[1]<x)
{
ans++;
}else
{
int p=query(x,1,n,1);
Update(p,p+x-1,0,1,n,1);
}
}else
{
y=read();
Update(x,y,1,1,n,1);
}
}
printf("%d\n",ans);
return 0;
}
BZOJ3062: [Usaco2013 Feb]Taxi
#include <cstdio>
#include <algorithm>
#include <cmath>
#include <cstdlib>
#include <cstring>
#include <queue>
#include <iostream>
using namespace std;
#define N 100005
int a[N],b[N],n,m;long long ans;
int main()
{
scanf("%d%d",&n,&m);
for(int i=1;i<=n;i++)
{
scanf("%d%d",&a[i],&b[i]);ans+=abs(b[i]-a[i]);
}
a[n+1]=m,b[n+1]=0;
sort(a+1,a+n+2);sort(b+1,b+n+2);
for(int i=1;i<=n+1;i++)ans+=abs(b[i]-a[i]);
printf("%lld\n",ans);
return 0;
}
BZOJ3063: [Usaco2013]Route Designing
#include <cstdio>
#include <algorithm>
#include <cmath>
#include <cstring>
#include <cstdlib>
#include <iostream>
#include <queue>
using namespace std;
#define N 100005
#define ll long long
struct node
{
int x,y;
friend bool operator<(const node &a,const node &b)
{
if(a.x==b.x)return a.y<b.y;
return a.x<b.x;
}
}e[N];
ll f[N],g[N],a[N],b[N];
int n,m,r;
int main()
{
scanf("%d%d%d",&n,&m,&r);
for(int i=1;i<=n;i++)scanf("%lld",&a[i]),f[i]=a[i];
for(int i=1;i<=m;i++)scanf("%lld",&b[i]),g[i]=b[i];
for(int i=1;i<=r;i++)scanf("%d%d",&e[i].x,&e[i].y);
sort(e+1,e+r+1);
for(int i=1;i<=r;i++)
{
int x=e[i].x,y=e[i].y;
ll t=f[x];
f[x]=max(g[y]+a[x],f[x]);
g[y]=max(t+b[y],g[y]);
}
ll ans=0;
for(int i=1;i<=n;i++)ans=max(ans,f[i]);
for(int i=1;i<=m;i++)ans=max(ans,g[i]);
printf("%lld\n",ans);
}
BZOJ3074: [Usaco2013 Mar]The Cow Run
#include <cstdio>
#include <cmath>
#include <algorithm>
#include <cstdlib>
#include <cstring>
#include <queue>
#include <iostream>
#include <set>
using namespace std;
#define N 1005
long long f[N][N],g[N][N];
int n,a[N];
int main()
{
memset(f,0x3f,sizeof(f));memset(g,0x3f,sizeof(g));
scanf("%d",&n);
for(int i=1;i<=n;i++)scanf("%d",&a[i]);
sort(a+1,a+n+1);
int p=lower_bound(a+1,a+n+1,0)-a;
if(p!=1)f[p-1][1]=g[p-1][1]=1ll*n*(0-a[p-1]);
if(a[p]>=0)f[p][1]=g[p][1]=1ll*n*(a[p]-0);
for(int i=2;i<=n;i++)
{
for(int j=1;j<=n-i+1;j++)
{
int k=i+j-1;
f[j][i]=min(f[j+1][i-1]+(n-i+1)*(a[j+1]-a[j]),g[j+1][i-1]+(n-i+1)*(a[k]-a[j]));
g[j][i]=min(f[j][i-1]+(a[k]-a[j])*(n-i+1),g[j][i-1]+(a[k]-a[k-1])*(n-i+1));
}
}
printf("%lld\n",min(f[1][n],g[1][n]));
return 0;
}
BZOJ3075: [Usaco2013]Necklace
#include <cstdio>
#include <algorithm>
#include <cmath>
#include <cstring>
#include <cstdlib>
#include <iostream>
#include <queue>
using namespace std;
#define N 10005
char str[N],sub[N];
int nxt[N],f[N][1005],n,m;
void get_next()
{
int j=0;nxt[1]=0;
for(int i=2;i<=m;i++)
{
while(sub[j+1]!=sub[i]&&j)j=nxt[j];
nxt[i]=(sub[j+1]==sub[i])?++j:0;
}
}
int main()
{
memset(f,0x3f,sizeof(f));
scanf("%s%s",str+1,sub+1);n=strlen(str+1),m=strlen(sub+1);get_next();
f[0][0]=0;
for(int i=1;i<=n;i++)
{
for(int j=0;j<m;j++)if(f[i-1][j]!=0x3f3f3f3f)
{
f[i][j]=min(f[i][j],f[i-1][j]+1);
int k=j;
while(k&&str[i]!=sub[k+1])k=nxt[k];
if(sub[k+1]==str[i])k++;
f[i][k]=min(f[i][k],f[i-1][j]);
}
}
int ans=1<<30;
for(int i=0;i<m;i++)ans=min(ans,f[n][i]);
printf("%d\n",ans);
}
BZOJ3126: [Usaco2013 Open]Photo
#include <cstdio>
#include <algorithm>
#include <cmath>
#include <cstring>
#include <cstdlib>
#include <queue>
#include <iostream>
using namespace std;
#define N 200005
int l1[N],r1[N],n,m,f[N],q[N];
int main()
{
scanf("%d%d",&n,&m);
for(int i=1;i<=n+1;i++)r1[i]=i-1;
for(int i=1;i<=m;i++)
{
int x,y;
scanf("%d%d",&x,&y);
l1[y+1]=max(x,l1[y+1]);r1[y]=min(x-1,r1[y]);
}
for(int i=n;i>=1;i--)r1[i]=min(r1[i+1],r1[i]);
for(int i=2;i<=n+1;i++)l1[i]=max(l1[i],l1[i-1]);
int h=0,t=0,j=1;
for(int i=1;i<=n+1;i++)
{
while(j<=r1[i]&&j<=n)
{
if(f[j]==-1){j++;continue;}
while(f[j]>f[q[t]]&&h<=t)t--;
q[++t]=j;j++;
}
while(l1[i]>q[h]&&h<=t)h++;
if(h<=t)f[i]=f[q[t]]+(i!=n+1);
else f[i]=-1;
}
printf("%d\n",f[n+1]);
return 0;
}
BZOJ3127: [Usaco2013 Open]Yin and Yang
#include <cstdio>
#include <cmath>
#include <algorithm>
#include <iostream>
#include <queue>
#include <cstring>
#include <cstdlib>
using namespace std;
#define N 100005
#define ll long long
int siz[N],mx[N],head[N],cnt,tot,sn,rot,vis[N],n,len;
struct node
{
int to,next,val;
}e[N<<1];
ll ans,f[N][2],g[N][2];
void add(int x,int y,int z)
{
e[cnt].to=y;
e[cnt].val=z;
e[cnt].next=head[x];
head[x]=cnt++;
}
void get_root(int x,int from)
{
siz[x]=1;mx[x]=0;
for(int i=head[x];i!=-1;i=e[i].next)
{
int to1=e[i].to;
if(to1!=from&&!vis[to1])
{
get_root(to1,x);
siz[x]+=siz[to1];
mx[x]=max(mx[x],siz[to1]);
}
}
mx[x]=max(mx[x],sn-siz[x]);
if(mx[rot]>mx[x])rot=x;
}
void calc(int x,int from,int now,int cnt)
{
if(now==0)
{
if(cnt>=2)ans++;
cnt++;
}
for(int i=head[x];i!=-1;i=e[i].next)
{
int to1=e[i].to;
if(to1!=from&&!vis[to1])
{
calc(to1,x,now+e[i].val,cnt);
}
}
}
void get_dep(int x,int from,int now,int l,int r)
{
if(l<=now&&now<=r)
{
if(now>=0)f[now][1]++;
else g[-now][1]++;
}else
{
if(now>=0)f[now][0]++;
else g[-now][0]++;
}
l=min(l,now);r=max(r,now);len=max(max(r,-l),len);
for(int i=head[x];i!=-1;i=e[i].next)
{
int to1=e[i].to;
if(!vis[to1]&&to1!=from)
{
get_dep(to1,x,now+e[i].val,l,r);
}
}
}
void dfs(int x)
{
vis[x]=1;calc(x,0,0,0);
get_dep(x,0,0,1,-1),ans+=f[0][1]*(f[0][1]-1)/2;f[0][0]=f[0][1]=0;
for(int i=1;i<=len;i++)ans+=f[i][0]*g[i][1]+g[i][0]*f[i][1]+f[i][1]*g[i][1],f[i][0]=f[i][1]=g[i][1]=g[i][0]=0;
for(int i=head[x];i!=-1;i=e[i].next)
{
int to1=e[i].to;
if(!vis[to1])
{
len=0;get_dep(to1,0,e[i].val,0,0);ans-=f[0][1]*(f[0][1]-1)/2;f[0][1]=f[0][0]=0;
for(int i=0;i<=len;i++)ans-=f[i][0]*g[i][1]+g[i][0]*f[i][1]+f[i][1]*g[i][1],f[i][0]=f[i][1]=g[i][1]=g[i][0]=0;
sn=siz[to1];
rot=0;get_root(to1,0);
dfs(rot);
}
}
}
int main()
{
memset(head,-1,sizeof(head));
scanf("%d",&n);
for(int i=1;i<n;i++)
{
int x,y,z;
scanf("%d%d%d",&x,&y,&z);
add(x,y,z*2-1);
add(y,x,z*2-1);
}
sn=n;mx[0]=n;
get_root(1,0);
dfs(rot);
printf("%lld\n",ans);
return 0;
}