8.21 usaco

summary：6

bzoj1692：//后缀数组就行了O(nlogn)c[30]会RE。。。注意！！！ 

#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
using namespace std;
#define rep(i,s,t) for(int i=s;i<=t;i++)
#define dwn(i,s,t) for(int i=s;i>=t;i--)
#define clr(x,c) memset(x,c,sizeof(x))
int read(){
	int x=0;char c=getchar();
	while(!isdigit(c)) c=getchar();
	while(isdigit(c)) x=x*10+c-'0',c=getchar();
	return x;
}
const int nmax=60005;
const int inf=0x7f7f7f7f;
char ss[5];int s[nmax],sa[nmax],t[nmax],t2[nmax],rank[nmax],c[nmax],n;
void build_sa(){
	int *x=t,*y=t2,m=29;
	for(int i=0;i<m;i++) c[i]=0;
	for(int i=0;i<n;i++) c[x[i]=s[i]]++;
	for(int i=1;i<m;i++) c[i]+=c[i-1];
	for(int i=n-1;i>=0;i--) sa[--c[x[i]]]=i;
	for(int k=1;k<=n;k<<=1){
		int p=0;
		for(int i=n-k;i<n;i++) y[p++]=i;
		for(int i=0;i<n;i++) if(sa[i]>=k) y[p++]=sa[i]-k;
		for(int i=0;i<m;i++) c[i]=0;
		for(int i=0;i<n;i++) c[x[i]]++;
		for(int i=1;i<m;i++) c[i]+=c[i-1];
		for(int i=n-1;i>=0;i--) sa[--c[x[y[i]]]]=y[i];
		swap(x,y);p=1;x[sa[0]]=0;
		for(int i=1;i<n;i++) 
		  x[sa[i]]=y[sa[i-1]]==y[sa[i]]&&y[sa[i-1]+k]==y[sa[i]+k]?p-1:p++;
		if(p>=n) break;
		m=p;
	}	
}
int main(){
	n=read();
	rep(i,0,n-1) scanf("%s",ss),s[i]=ss[0]-'A'+1;
	s[n]=0;
	rep(i,1,n) s[n+i]=s[n-i];
	int tn=n;n*=2;++n;
	
	build_sa();
	rep(i,0,n-1) rank[sa[i]]=i;
	int l=0,r=tn-1;;
	rep(i,1,tn){
		if(rank[l]<rank[tn-r+tn]) putchar(s[l++]+'A'-1);
		else putchar(s[r--]+'A'-1);
		if(i%80==0) putchar('
');
	}
	return 0;
}

bzoj1697：置换群（感觉好神啊。。。

#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
using namespace std;
#define rep(i,s,t) for(int i=s;i<=t;i++)
#define dwn(i,s,t) for(int i=s;i>=t;i--)
#define clr(x,c) memset(x,c,sizeof(x))
int read(){
	int x=0,f=1;char c=getchar();
	while(!isdigit(c)) {
		if(c=='-') f=-1;c=getchar();
	}
	while(isdigit(c)) x=x*10+c-'0',c=getchar();
	return x*f;
}
const int nmax=1e4+5;
const int maxn=1e5+5;
const int inf=0x7f7f7f7f;
int a[nmax],to[maxn],b[nmax],mn,n;
bool vis[nmax];
void mins(int &a,int b){
	if(a>b) a=b;
}
int solve(int x){
	int tmn=a[x],cnt=1,sum=a[x];vis[x]=1;
	for(int tmp=to[b[x]];tmp!=x;tmp=to[b[tmp]]) 
	  cnt++,mins(tmn,a[tmp]),sum+=a[tmp],vis[tmp]=1;
	return min(sum+(cnt-2)*tmn,sum+tmn+(cnt+1)*mn);
}
int main(){
	n=read(),mn=inf;
	rep(i,1,n) a[i]=b[i]=read(),mins(mn,a[i]),to[a[i]]=i;
	sort(b+1,b+n+1);
	int ans=0;
	rep(i,1,n) if(!vis[i]) ans+=solve(i);
	printf("%d
",ans);
	return 0;
}

bzoj1703：bitset优化传递闭包。

#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
#include<bitset>
using namespace std;
#define rep(i,s,t) for(int i=s;i<=t;i++)
#define dwn(i,s,t) for(int i=s;i>=t;i--)
#define clr(x,c) memset(x,c,sizeof(x))
#define qwq(x) for(edge *o=head[x];o;o=o->next)
int read(){
	int x=0;char c=getchar();
	while(!isdigit(c)) c=getchar();
	while(isdigit(c)) x=x*10+c-'0',c=getchar();
	return x;
}
const int nmax=1005;
const int maxn=10005;
const int inf=0x7f7f7f7f;
bitset<nmax>a[nmax];
struct edge{
	int to;edge *next;
};
edge es[maxn],*pt=es,*head[nmax];
bool vis[nmax];
void add(int u,int v){
	pt->to=v;pt->next=head[u];head[u]=pt++;
}
void dfs(int x){
	vis[x]=1;
	qwq(x) {
		if(!vis[o->to]) dfs(o->to);
		a[x]|=a[o->to];
	}
}
int main(){
	int n=read(),m=read(),u,v;
	rep(i,1,m) u=read(),v=read(),add(u,v);
	rep(i,1,n) a[i][i]=1;
	rep(i,1,n) if(!vis[i]) dfs(i);
	int ans=0;
	rep(i,1,n) printf("%d ",a[i].count());printf("
");
	rep(i,1,n) ans+=a[i].count();
	printf("%d
",n*(n-1)/2-ans+n);
	return 0;
}

bzoj1704：写了O(n^3)想要卡过去结果tle了。。。异或异或异或！！！可以利用异或的性质O(n^2)

#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
using namespace std;
#define rep(i,s,t) for(int i=s;i<=t;i++)
#define dwn(i,s,t) for(int i=s;i>=t;i--)
#define clr(x,c) memset(x,c,sizeof(x))
const int nmax=5005;
const int inf=0x7f7f7f7f;
char s[5];int a[nmax],b[nmax];
int main(){
	int n;scanf("%d",&n);
	rep(i,1,n) {
		scanf("%s",s);
		a[i]=s[0]=='F'?0:1;
	}
	dwn(i,n,2) a[i]=a[i]==a[i-1]?0:1;
	int ans,res=inf,cnt;bool flag;
	rep(i,1,n) {
		cnt=0;flag=true;
		rep(j,1,n) b[j]=a[j];
		rep(j,1,n) if(b[j]) {
			if(j+i-1<=n) cnt++,b[j+i]^=1;
			else {
				flag=false;break;
			}
		}
		if(flag&&cnt<res) ans=i,res=cnt;
	}
	printf("%d %d
",ans,res);
	return 0;
} 

ch11：没有考虑0.499999的情况WA了一个点还好没有卡精度啊QAQ看题不仔细！懒得改了。。。

#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
using namespace std;
#define rep(i,s,t) for(int i=s;i<=t;i++)
#define clr(x,c) memset(x,c,sizeof(x))
int read(){
	int x=0,f=1;char c=getchar();
	while(!isdigit(c)){
		if(c=='-') f=-1;c=getchar();
	}
	while(isdigit(c)) x=x*10+c-'0',c=getchar();
	return x*f;
}
int main(){
	double sum=0;
	int t=read();
	while(t--){
		int n=read(),u;
		double sum=0;
		rep(i,1,n) u=read(),sum+=u*1.0;
		if(sum-0.5*n<=100.0&&sum+0.4*n>=100.0) 
		  printf("Yes
");
		else printf("No
");
	}
	return 0;
}

ch12：树状数组+n数码判有无解。没有看好数据范围没开longlong。。。都是一些以为自己不会犯的错误啊。。。懒得改了。

#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
using namespace std;
#define rep(i,s,t) for(int i=s;i<=t;i++)
#define clr(x,c) memset(x,c,sizeof(x))
int read(){
	int x=0;char c=getchar();
	while(!isdigit(c)) c=getchar();
	while(isdigit(c)) x=x*10+c-'0',c=getchar();
	return x;
}
const int nmax=250005;
int sum[nmax],n;
int query(int x){
	int ans=0;
	for(int i=x;i;i-=i&-i) ans+=sum[i];
	return ans;
}
void add(int x){
	for(int i=x;i<=n*n;i+=i&-i) sum[i]+=1;
}
int main(){
	while(scanf("%d",&n)!=EOF){
		clr(sum,0);
		int u,ans=0,res=0;
		rep(i,1,n) rep(j,1,n){
			u=read();if(!u) continue;
			ans+=query(u);add(u);
		}
		clr(sum,0);
		rep(i,1,n) rep(j,1,n) {
			u=read();if(!u) continue;
			res+=query(u);add(u);
		}
		if((ans%2)!=(res%2)) printf("NIE
");
		else printf("TAK
");
	}
	return 0;
}