一般图最大带权匹配:高级带花树

有个两百多行的板子,没有注释,看着好像挺对的,先挖个坑以后填。

  1 #include <bits/stdc++.h>
  2 #define N 810
  3 using namespace std;
  4 typedef long long ll;
  5 inline int read()
  6 {
  7     int x=0,f=1; char ch=getchar();
  8     while(ch<'0'||ch>'9'){if(ch=='-')f=-1; ch=getchar();}
  9     while(ch>='0'&&ch<='9'){x=x*10+ch-'0'; ch=getchar();}
 10     return x*f;
 11 }
 12 struct edge{int u,v,w;}mps[N][N];
 13 int n,m,mat[N],pre[N],bl[N],fa[N],tim;ll totw=0;
 14 int sign[N],lab[N],slacku[N],blofm[N][N],tot,mx;
 15 vector <int> leaves[N];
 16 int q[N],hd;
 17 inline int calc_e(const edge &e)
 18 {
 19     return lab[e.u]+lab[e.v]-mps[e.u][e.v].w*2;
 20 }
 21 inline void updata(int u,int x)
 22 {
 23     if(!slacku[x]||calc_e(mps[u][x])<calc_e(mps[slacku[x]][x]))
 24         slacku[x]=u;
 25 }
 26 inline void calc_slack(int x)
 27 {
 28     slacku[x]=0; 
 29     for(int i=1;i<=n;i++)
 30         if(mps[i][x].w>0&&fa[i]!=x&&sign[fa[i]]==0)
 31             updata(i,x);
 32 }
 33 inline void q_push(int x)
 34 {
 35     if(x<=n) q[++hd]=x;
 36     else for(int i=0;i<(int)leaves[x].size();i++)
 37         q_push(leaves[x][i]); 
 38 }
 39 inline int get_lca(int x, int y)
 40 {
 41     if(tim=100000000) 
 42         memset(bl,0,sizeof bl),tim=0;
 43     for(++tim;x||y;swap(x,y)) if(x)
 44     {
 45         if(bl[x]==tim) return x;
 46         bl[x]=tim; x=fa[mat[x]];
 47         if(x) x=fa[pre[x]];
 48     }
 49     return 0;
 50 }
 51 inline void set_fa(int x,int y)
 52 {
 53     fa[x]=y; if(x>n) 
 54     for(int i=0;i<(int)leaves[x].size();i++)
 55         set_fa(leaves[x][i],y);
 56 }
 57 inline void set_mat(int x,int y)
 58 {
 59     mat[x]=mps[x][y].v;
 60     if(x<=n) return ;
 61     int xr=blofm[x][mps[x][y].u];
 62     int pr=find(leaves[x].begin(),leaves[x].end(),xr)-leaves[x].begin();
 63     if(pr%2==1)
 64         reverse(leaves[x].begin()+1, leaves[x].end()),
 65         pr=(int)leaves[x].size()-pr;
 66     for(int i=0;i<pr;i++)
 67         set_mat(leaves[x][i],leaves[x][i^1]);
 68     set_mat(xr,y);
 69     rotate(leaves[x].begin(),leaves[x].begin()+pr,leaves[x].end());
 70 }
 71 inline void blossom_blooms(int x)
 72 {
 73     for(int i=0;i<(int)leaves[x].size();i++)
 74     {
 75         if(leaves[x][i]>n&&!lab[leaves[x][i]])
 76             blossom_blooms(leaves[x][i]);
 77         else set_fa(leaves[x][i],leaves[x][i]);
 78     }
 79     fa[x]=0;
 80 }
 81 inline void blossom_make(int u,int lca,int v)
 82 {
 83     int x=n+1; while(x<=tot&&fa[x]) x++;
 84     if(x>tot) tot++; 
 85     lab[x]=sign[x]=0;
 86     mat[x]=mat[lca]; leaves[x].clear();
 87     leaves[x].push_back(lca);
 88     for(int i=u;i!=lca;i=fa[pre[fa[mat[i]]]])
 89         leaves[x].push_back(i),leaves[x].push_back(fa[mat[i]]),q_push(fa[mat[i]]);
 90     reverse(leaves[x].begin()+1, leaves[x].end());
 91     for(int i=v;i!=lca;i=fa[pre[fa[mat[i]]]])
 92         leaves[x].push_back(i),leaves[x].push_back(fa[mat[i]]),q_push(fa[mat[i]]);
 93     set_fa(x,x);
 94     for(int i=1;i<=tot;i++)
 95         mps[x][i].w=mps[i][x].w=0, blofm[x][i]=0;
 96     for(int i=0;i<(int)leaves[x].size();i++)
 97     {
 98         int xs=leaves[x][i];
 99         for(int j=1;j<=tot;j++)
100             if(!mps[x][j].w||calc_e(mps[xs][j])<calc_e(mps[x][j]))
101                 mps[x][j]=mps[xs][j],mps[j][x]=mps[j][xs];
102         for(int j=1;j<=tot;j++)
103             if(blofm[xs][j]) blofm[x][j]=xs;
104     }
105     calc_slack(x);
106 }
107 inline void link(int x,int y)
108 {
109     while(1)
110     {
111         int xx=fa[mat[x]];
112         set_mat(x,y);
113         if(!xx) return ;
114         set_mat(xx,fa[pre[xx]]);
115         x=fa[pre[xx]]; y=xx;
116     }
117 }
118 inline int deal_edge(const edge &e)
119 {
120     int u=fa[e.u],v=fa[e.v];
121     if(sign[v]==-1) //unsigned
122     {
123         pre[v]=e.u; // cause we bfs all vertices tegother,we dont' need to discuss two situation 
124         sign[v]=1; sign[fa[mat[v]]]=0;
125         slacku[v]=slacku[fa[mat[v]]]=0;
126         q_push(fa[mat[v]]);
127     }
128     else if(!sign[v]) //S signed vertex
129     {
130         int lca=get_lca(u,v);
131         if(!lca)
132         {
133             link(u,v); link(v,u); //connected! new argument.
134             for(int i=n+1;i<=tot;i++)
135                 if(fa[i]==i&&lab[i]==0)
136                     blossom_blooms(i); // flower may not be a flower any more so we blossom blooms!
137             return 1;
138         }
139         else blossom_make(u,lca,v); // form a new flower!
140     }
141     return 0;
142 }
143 inline void blossom_bloom_1(int x)
144 {
145 
146     for(int i=0;i<(int)leaves[x].size();i++)
147         set_fa(leaves[x][i],leaves[x][i]);
148     int xr=blofm[x][mps[x][pre[x]].u];
149     int pr=find(leaves[x].begin(), leaves[x].end(),xr)-leaves[x].begin();
150     if(pr%2==1) 
151         reverse(leaves[x].begin()+1, leaves[x].end()),
152         pr=(int)leaves[x].size()-pr;
153     for(int i=0;i<pr;i+=2)
154     {
155         int u=leaves[x][i],v=leaves[x][i+1];
156         pre[u]=mps[v][u].u;
157         sign[u]=1; sign[v]=0;
158         slacku[u]=0; calc_slack(v); q_push(v);
159     }    
160     sign[xr]=1; pre[xr]=pre[x];
161     for(int i=pr+1;i<(int)leaves[x].size();i++)
162     {
163         int u=leaves[x][i];
164         sign[u]=-1; calc_slack(u);
165     }
166     fa[x]=0;
167 }
168 inline int match()
169 {
170     for(int i=1;i<=tot;i++) slacku[i]=0,sign[i]=-1;
171     hd=0; for(int i=1;i<=tot;i++)
172         if(fa[i]==i&&!mat[i])
173             slacku[i]=pre[i]=sign[i]=0,q_push(i);
174     if(!hd) return 0; 
175     while(1)
176     {
177         for(int i=1;i<=hd;i++)
178         {
179             int lx=q[i]; for(int j=1;j<=n;j++)
180                 if(mps[lx][j].w>0&&fa[lx]!=fa[j])
181                 {
182                     if(!calc_e(mps[lx][j]))
183                     {
184                         if(deal_edge(mps[lx][j])) 
185                             return 1;
186                     }
187                     else if(sign[fa[j]]!=1) updata(lx,fa[j]);
188                 }
189         }
190         int d=0x3fffffff;
191         for(int i=1;i<=n;i++) if(!sign[fa[i]])
192             d=min(d,lab[i]);
193         for(int i=n+1;i<=tot;i++)
194             if(fa[i]==i&&sign[i]==1)
195                 d=min(lab[i]/2,d);
196         for(int i=1;i<=tot;i++) if(fa[i]==i&&slacku[i])
197         {
198             if(sign[i]==-1) d=min(calc_e(mps[slacku[i]][i]),d);
199             else if(sign[i]==0) d=min(calc_e(mps[slacku[i]][i])/2,d);
200         }
201         for(int i=1;i<=n;i++)
202             if(sign[fa[i]]==0) lab[i]-=d;
203             else if (sign[fa[i]]==1) lab[i]+=d;
204         for(int i=n+1;i<=tot;i++)
205             if(fa[i]==i)
206             {
207                 if(sign[i]==0) lab[i]+=d*2; 
208                 else if(sign[i]==1) lab[i]-=d*2;
209             }
210         hd=0;
211         for(int i=1;i<=n;i++) if(!lab[i]) return 0; //all vetices matched,single vetices's label = 0
212         for(int i=1;i<=tot;i++)
213             if(fa[i]==i&&slacku[i]&&fa[slacku[i]]!=i&&calc_e(mps[slacku[i]][i])==0)
214                 /*new edge*/ if(deal_edge(mps[slacku[i]][i])) return 1;
215         for(int i=n+1;i<=tot;i++)
216             if(fa[i]==i&&sign[i]==1&&!lab[i])
217                 blossom_bloom_1(i);
218     }
219     return 0;
220 }
221 inline void solve()
222 {
223     for(int i=1;i<=n;i++) mat[i]=0;
224     tot=n; hd=totw=0;  
225     for(int i=0;i<=n;i++) fa[i]=i,leaves[i].clear();
226     for(int i=1;i<=n;i++) for(int j=1;j<=n;j++)
227         blofm[i][j]=(i==j? i:0);
228     for(int i =1;i<=n;i++) lab[i]=mx; //init label
229     while(match());
230     for(int i=1;i<=n;i++) if(mat[i]&&mat[i]<i)
231         totw+=mps[i][mat[i]].w;
232 }
233 int main()
234 {
235     n=read(); m=read();
236     for(int i=1;i<=n;i++)
237         for(int j=1;j<=n;j++)
238             mps[i][j]=(edge){i,j,0};
239     for(int i=1;i<=m;i++)
240     {
241         int u=read(), v=read(), w=read();
242         mps[u][v].w=mps[v][u].w=w; mx=max(mx,w);
243     }
244     solve(); printf("%lld\n",totw);
245     for(int i=1;i<=n;i++)
246         printf("%d ",mat[i]); 
247     puts("");
248     return 0;
249 }

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转载自www.cnblogs.com/St-Lovaer/p/11945741.html