BZOJ.5251.[八省联考2018]劈配mentor(最大流)
对于每个人,每次枚举一个志愿看是否能增广即可。
对于第二问,可以保留第一问中\(n\)次增广前后的\(n\)张图,二分,在对应图上看是否能增广即可。
貌似匈牙利的某种写法比网络流优多了...懒得看...
写的常数莫名大...
增广失败的话原图流量不会变啊,不用特意删掉新加的边,把表头head改了即可,而且判断是否能增广只需要判断BFS()是否返回1。
Dinic:
//195228kb 6676ms
#include <cstdio>
#include <cctype>
#include <vector>
#include <cstring>
#include <algorithm>
#define gc() getchar()
typedef long long LL;
const int N=408,M=(N+40005)*2,INF=0x3f3f3f3f;
int T;
struct Graph
{
int Enum,H[N],nxt[M],to[M],cap[M],cur[N],lev[N];
inline void Init(int n)
{
Enum=1, memset(H,0,n+1<<2);
}
inline void AE(int u,int v,int w)
{
to[++Enum]=v, nxt[Enum]=H[u], H[u]=Enum, cap[Enum]=w;
to[++Enum]=u, nxt[Enum]=H[v], H[v]=Enum, cap[Enum]=0;
}
bool BFS()
{
static int q[N];
memset(lev,0,T+1<<2);
int h=0,t=1; q[0]=0, lev[0]=1;
while(h<t)
{
int x=q[h++];
for(int i=H[x]; i; i=nxt[i])
if(!lev[to[i]] && cap[i])
{
q[t++]=to[i], lev[to[i]]=lev[x]+1;
if(to[i]==T) return 1;
}
}
return 0;
}
int DFS(int x,int flow)
{
if(x==T) return flow;
int used=0;
for(int &i=cur[x]; i; i=nxt[i])
if(lev[to[i]]==lev[x]+1 && cap[i])
{
int delta=DFS(to[i],std::min(flow,cap[i]));
if(delta)
{
cap[i]-=delta, cap[i^1]+=delta, used+=delta;
if(used==flow) return flow;
}
}
return lev[x]=0,used;
}
void Dinic()
{
while(BFS()) memcpy(cur,H,T+1<<2), DFS(0,INF);
}
}G[203];
inline int read()
{
int now=0;register char c=gc();
for(;!isdigit(c);c=gc());
for(;isdigit(c);now=now*10+c-48,c=gc());
return now;
}
int main()
{
static int B[203],s[203],Ans1[203],tmpH[N];
static std::vector<int> v[203][203];
freopen("mentor.in","r",stdin);
freopen("mentor.out","w",stdout);
for(int Tests=read(),C=read(); Tests--; )
{
int n=read(),m=read(); T=n+m+1;
G[0].Init(T);
for(int i=1; i<=n; ++i) G[0].AE(0,i,1);
for(int i=1; i<=m; ++i) G[0].AE(i+n,T,B[i]=read());
for(int i=1; i<=n; ++i)
for(int j=1; j<=m; ++j) v[i][j].clear();
for(int i=1; i<=n; ++i)
for(int j=1; j<=m; ++j) v[i][read()].push_back(j+n);
for(int i=1; i<=n; ++i) s[i]=read();
for(int i=1; i<=n; ++i)
{
G[i]=G[i-1];
int j;
for(j=1; j<=m; ++j)
{
std::vector<int> &vec=v[i][j];
for(int k=0,l=vec.size(); k<l; ++k) G[i].AE(i,vec[k],1);
if(G[i].BFS()) {G[i].Dinic(); break;}
if(vec.size()) G[i].Enum=G[i-1].Enum, memcpy(G[i].H,G[i-1].H,T+1<<2);
}
printf("%d ",Ans1[i]=j);
}
putchar('\n');
for(int i=1; i<=n; ++i)
if(Ans1[i]<=s[i]) putchar('0'), putchar(' ');
else
{
int l=1,r=i-1,mid,ans=0,dream=s[i];
while(l<=r)
{
mid=l+r>>1;
int tmpEnum=G[mid-1].Enum;
memcpy(tmpH,G[mid-1].H,T+1<<2);
bool ok=0;
for(int j=1; j<=dream; ++j)
{
std::vector<int> &vec=v[i][j];
for(int k=0,l=vec.size(); k<l; ++k) G[mid-1].AE(i,vec[k],1);
if(G[mid-1].BFS()) {ok=1; break;}
}
if(ok) ans=mid, l=mid+1;
else r=mid-1;
G[mid-1].Enum=tmpEnum, memcpy(G[mid-1].H,tmpH,T+1<<2);
}
printf("%d ",i-ans);
}
putchar('\n');
}
return 0;
}
ISAP:
//259320kb 7584ms
#include <cstdio>
#include <cctype>
#include <vector>
#include <cstring>
#include <algorithm>
#define gc() getchar()
typedef long long LL;
const int N=408,M=(N+40005)*2,INF=0x3f3f3f3f;
int T;
struct Graph
{
int Enum,H[N],nxt[M],fr[M],to[M],cap[M],pre[N],lev[N];
inline void Init(int n)
{
Enum=1, memset(H,0,n+1<<2);
}
inline void AE(int u,int v,int w)
{
to[++Enum]=v, nxt[Enum]=H[u], H[u]=Enum, fr[Enum]=u, cap[Enum]=w;
to[++Enum]=u, nxt[Enum]=H[v], H[v]=Enum, fr[Enum]=v, cap[Enum]=0;
}
bool BFS()
{
static int q[N];
const int lim=T+1;
for(int i=0; i<T; ++i) lev[i]=lim;
int h=0,t=1; q[0]=T, lev[T]=0;
while(h<t)
{
int x=q[h++];
for(int i=H[x]; i; i=nxt[i])
if(cap[i^1] && lev[to[i]]==lim) q[t++]=to[i], lev[to[i]]=lev[x]+1;
}
return lev[0]<=T;
}
inline void Augment()
{
// int mn=INF;
// for(int i=T; i; i=fr[pre[i]])
// mn=std::min(mn,cap[pre[i]]);
for(int i=T; i; i=fr[pre[i]])
--cap[pre[i]], ++cap[pre[i]^1];
}
void ISAP()
{
static int cur[N],num[N];
memset(num,0,T+1<<2);
for(int i=0; i<=T; ++i) cur[i]=H[i], ++num[lev[i]];
int x=0;
while(lev[0]<=T)
{
if(x==T) x=0, Augment();
bool can=0;
for(int i=cur[x]; i; i=nxt[i])
if(lev[to[i]]==lev[x]-1 && cap[i])
{
can=1, cur[x]=i, pre[x=to[i]]=i;
break;
}
if(!can)
{
int mn=T;
for(int i=H[x]; i; i=nxt[i])
if(cap[i]) mn=std::min(mn,lev[to[i]]);
if(!--num[lev[x]]) break;
++num[lev[x]=mn+1], cur[x]=H[x];
if(x) x=fr[pre[x]];
}
}
}
}G[203];
inline int read()
{
int now=0;register char c=gc();
for(;!isdigit(c);c=gc());
for(;isdigit(c);now=now*10+c-48,c=gc());
return now;
}
int main()
{
static int B[203],s[203],Ans1[203],tmpH[N];
static std::vector<int> v[203][203];
freopen("mentor.in","r",stdin);
freopen("mentor.out","w",stdout);
for(int Tests=read(),C=read(); Tests--; )
{
int n=read(),m=read(); T=n+m+1;
G[0].Init(T);
for(int i=1; i<=n; ++i) G[0].AE(0,i,1);
for(int i=1; i<=m; ++i) G[0].AE(i+n,T,B[i]=read());
for(int i=1; i<=n; ++i)
for(int j=1; j<=m; ++j) v[i][j].clear();
for(int i=1; i<=n; ++i)
for(int j=1; j<=m; ++j) v[i][read()].push_back(j+n);
for(int i=1; i<=n; ++i) s[i]=read();
for(int i=1; i<=n; ++i)
{
G[i]=G[i-1];
int j;
for(j=1; j<=m; ++j)
{
std::vector<int> &vec=v[i][j];
for(int k=0,l=vec.size(); k<l; ++k) G[i].AE(i,vec[k],1);
if(G[i].BFS()) {G[i].ISAP(); break;}
if(vec.size()) G[i].Enum=G[i-1].Enum, memcpy(G[i].H,G[i-1].H,T+1<<2);
}
printf("%d ",Ans1[i]=j);
}
putchar('\n');
for(int i=1; i<=n; ++i)
if(Ans1[i]<=s[i]) putchar('0'), putchar(' ');
else
{
int l=1,r=i-1,mid,ans=0,dream=s[i];
while(l<=r)
{
mid=l+r>>1;
int tmpEnum=G[mid-1].Enum;
memcpy(tmpH,G[mid-1].H,T+1<<2);
bool ok=0;
for(int j=1; j<=dream; ++j)
{
std::vector<int> &vec=v[i][j];
for(int k=0,l=vec.size(); k<l; ++k) G[mid-1].AE(i,vec[k],1);
if(G[mid-1].BFS()) {ok=1; break;}
}
if(ok) ans=mid, l=mid+1;
else r=mid-1;
G[mid-1].Enum=tmpEnum, memcpy(G[mid-1].H,tmpH,T+1<<2);
}
printf("%d ",i-ans);
}
putchar('\n');
}
return 0;
}
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很久以前的奇怪但现在依旧成立的签名
attack is our red sun $$\color{red}{\boxed{\color{red}{attack\ is\ our\ red\ sun}}}$$ ------------------------------------------------------------------------------------------------------------------------
很久以前的奇怪但现在依旧成立的签名
attack is our red sun $$\color{red}{\boxed{\color{red}{attack\ is\ our\ red\ sun}}}$$ ------------------------------------------------------------------------------------------------------------------------