bzoj3882 [Wc2015]K小割

  1 //It is made by wfj_2048~
  2 #include <algorithm>
  3 #include <iostream>
  4 #include <cstring>
  5 #include <cstdlib>
  6 #include <cstdio>
  7 #include <vector>
  8 #include <cmath>
  9 #include <queue>
 10 #include <stack>
 11 #include <map>
 12 #include <set>
 13 #define inf (1<<28)
 14 #define il inline
 15 #define RG register
 16 #define ll long long
 17 
 18 using namespace std;
 19 
 20 struct E{ int u,v,w; }G[500010];
 21 
 22 int n,m,k,S,T,mx;
 23 
 24 il int gi(){
 25     RG int x=0,q=1; RG char ch=getchar();
 26     while ((ch<‘0‘ || ch>‘9‘) && ch!=‘-‘) ch=getchar();
 27     if (ch==‘-‘) q=-1,ch=getchar();
 28     while (ch>=‘0‘ && ch<=‘9‘) x=x*10+ch-48,ch=getchar();
 29     return q*x;
 30 }
 31 
 32 namespace brute{
 33     
 34     struct edge{ int nt,to; }g[22];
 35     
 36     int head[12],vi[12],vis[22],top,num;
 37     ll st[2000010];
 38     
 39     il void insert(RG int from,RG int to){
 40     g[++num]=(edge){head[from],to},head[from]=num; return;
 41     }
 42     
 43     il int find(RG int x,RG int T){
 44     if (x==T) return 1; vi[x]=1; RG int v;
 45     for (RG int i=head[x];i;i=g[i].nt){
 46         v=g[i].to; if (vi[v]) continue;
 47         if (find(v,T)) return 1;
 48     }
 49     return 0;
 50     }
 51     
 52     il int check(){
 53     memset(head,0,sizeof(head)),num=0;
 54     for (RG int i=1;i<=m;++i)
 55         if (!vis[i]) insert(G[i].u,G[i].v);
 56     memset(vi,0,sizeof(vi)); return !find(S,T);
 57     }
 58     
 59     il void dfs(RG int x,RG ll tot){
 60     if (x>m){
 61         if (check()) st[++top]=tot;
 62         return;
 63     }
 64     vis[x]=1,dfs(x+1,tot+G[x].w);
 65     vis[x]=0,dfs(x+1,tot); return;
 66     }
 67     
 68     int main(){
 69     dfs(1,0),sort(st+1,st+top+1);
 70     for (RG int i=1;i<=top && i<=k;++i) printf("%lld\n",st[i]);
 71     if (top<k) puts("-1"); return 0;
 72     }
 73     
 74 }
 75 
 76 namespace heap{
 77     
 78     struct data{
 79     ll val; int i,level;
 80     il bool operator < (const data &a) const{ return val>a.val; }
 81     };
 82     
 83     struct node{ ll a,b; }e[200010];
 84     
 85     priority_queue <data> Q;
 86     
 87     ll mincut;
 88     
 89     il int cmp(const node &x,const node &y){
 90     if (x.a==y.a) return x.b<y.b; return x.a<y.a;
 91     }
 92     
 93     int main(){
 94     for (RG int i=1,x;i<=m;++i){
 95         x=G[i].u; if (x==S || x==T) x=G[i].v;
 96         if (!e[x].a) e[x].a=G[i].w; else{
 97         e[x].b=G[i].w;
 98         if (e[x].a<e[x].b) swap(e[x].a,e[x].b);
 99         mincut+=e[x].b,e[x].a-=e[x].b;
100         }
101     }
102     if (T==n) e[S]=e[n-1],e[T]=e[n]; else e[S]=e[n],e[T]=e[n-1];
103     n-=2,--k,sort(e+1,e+n+1,cmp),printf("%lld\n",mincut);
104     Q.push((data){mincut+e[1].a,1,1});
105     for (;k && !Q.empty();--k){
106         RG data x=Q.top(),tmp; Q.pop();
107         printf("%lld\n",x.val);
108         if (x.level<2){
109         tmp.val=x.val+e[x.i].b;
110         tmp.i=x.i,tmp.level=x.level+1,Q.push(tmp);
111         }
112         if (x.i<n && x.level==1){
113         tmp.val=x.val-e[x.i].a+e[x.i+1].a;
114         tmp.i=x.i+1,tmp.level=1,Q.push(tmp);
115         }
116         if(x.i<n){
117         tmp.val=x.val+e[x.i+1].a;
118         tmp.i=x.i+1,tmp.level=1,Q.push(tmp);
119         }
120     }
121     if (k) puts("-1"); return 0;
122     }
123     
124 }
125 
126 namespace kthcut{
127 
128 #define M (3005)
129 #define N (60)
130     
131     int head[N],cur[N],havs[N],havt[N],ds[N],dt[N],d[N],vis[N],in[M],q[10*M],num=1;
132     
133     struct Graph{
134      
135     struct edge{ int nt,to,flow,cap; }g[M];
136     
137     il void insert(RG int from,RG int to,RG int cap){
138         g[++num]=(edge){head[from],to,0,cap},head[from]=num; return;
139     }
140     
141     il int bfs(RG int S,RG int T){
142         memset(d,0,sizeof(d)),d[S]=1;
143         RG int h=0,t=1; q[t]=S;
144         while (h<t){
145         RG int x=q[++h],v;
146         for (RG int i=head[x];i;i=g[i].nt){
147             v=g[i].to;
148             if (!d[v] && g[i].cap>g[i].flow){
149             d[v]=d[x]+1,q[++t]=v;
150             if (v==T) return 1;
151             }
152         }
153         }
154         return d[T];
155     }
156     
157     il ll dfs(RG int x,RG int T,RG int a){
158         if (!a || x==T) return a; RG ll flow=0,f;
159         for (RG int &i=cur[x],v;i;i=g[i].nt){
160         v=g[i].to;
161         if (d[v]==d[x]+1 && g[i].cap>g[i].flow){
162             f=dfs(v,T,min(a,g[i].cap-g[i].flow));
163             if (!f){ d[v]=0; continue; }
164             g[i].flow+=f,g[i^1].flow-=f;
165             flow+=f,a-=f; if (!a) return flow;
166         }
167         }
168         return flow;
169     }
170     
171     il ll mincut(RG int S,RG int T){
172         RG ll cut=0;
173         while (bfs(S,T)){
174         memcpy(cur,head,sizeof(head));
175         cut+=dfs(S,T,inf); if (cut>inf) return cut;
176         }
177         return cut;
178     }
179     
180     il void DFS(RG int x){
181         vis[x]=1;
182         for (RG int i=head[x];i;i=g[i].nt)
183         if (g[i].cap>g[i].flow && !vis[g[i].to]) DFS(g[i].to);
184         return;
185     }
186     
187     il void getcut(){
188         memset(vis,0,sizeof(vis)),memset(in,0,sizeof(in)),DFS(S);
189         for (RG int i=1;i<=m;++i) if (vis[G[i].u] && !vis[G[i].v]) in[i]=1;
190         return;
191     }
192     
193     }Gra,lin1,lin2;
194     
195     struct node{
196     
197     int must[M],stop[M],id,ww; ll val;
198     
199     il bool operator < (const node &a) const{ return val>a.val; }
200     
201     il void build(){
202         val=0,lin1=Gra;
203         for (RG int i=1;i<=m;++i)
204         if (must[i]) val+=G[i].w,lin1.g[i<<1].cap=0;
205         else if (stop[i]) lin1.g[i<<1].cap=inf;
206         val+=lin1.mincut(S,T),lin1.getcut(),ww=inf,id=0;
207         memset(havs,0,sizeof(havs)),memset(havt,0,sizeof(havt));
208         for (RG int i=1;i<=m;++i){
209         if (must[i] || stop[i]) continue;
210         if (in[i]){
211             if (!havs[G[i].u]){
212             havs[G[i].u]=1,lin2=lin1;
213             ds[G[i].u]=lin2.mincut(S,G[i].u);
214             }
215             if (!havt[G[i].v]){
216             havt[G[i].v]=1,lin2=lin1;
217             dt[G[i].v]=lin2.mincut(G[i].v,T);
218             }
219             if (ds[G[i].u]<ww) ww=ds[G[i].u],id=i;
220             if (dt[G[i].v]<ww) ww=dt[G[i].v],id=i;
221         } else if (G[i].w<ww) ww=G[i].w,id=i;
222         }
223         val+=ww; return;
224     }
225     
226     }a,b;
227     
228     priority_queue <node> Q;
229     
230     int main(){
231     for (RG int i=1;i<=m;++i){
232         Gra.insert(G[i].u,G[i].v,G[i].w);
233         Gra.insert(G[i].v,G[i].u,0);
234     }
235     --k,lin1=Gra,printf("%lld\n",lin1.mincut(S,T));
236     a.build(); if (a.val<inf) Q.push(a);
237     for (;k && !Q.empty();--k){
238         a=b=Q.top(),Q.pop(),printf("%lld\n",a.val);
239         a.must[a.id]=1,a.build(); if (a.val<inf) Q.push(a);
240         b.stop[b.id]=1,b.build(); if (b.val<inf) Q.push(b);
241     }
242     if (k) puts("-1"); return 0;
243     }
244          
245 }
246 
247 int main(){
248 #ifndef ONLINE_JUDGE
249     freopen("kthcut.in","r",stdin);
250     freopen("kthcut.out","w",stdout);
251 #endif
252     n=gi(),m=gi(),S=gi(),T=gi(),k=gi();
253     for (RG int i=1;i<=m;++i)
254     G[i].u=gi(),G[i].v=gi(),G[i].w=gi(),mx=max(mx,G[i].w);
255     if (m<=20) brute::main();
256     else if (n<=50 && k<=100 && mx<=65536) kthcut::main();
257     else heap::main();
258     return 0;
259 }