"UVA 753" A Plug for UNIX (graph theory-Maximum flow dinic)

Test Instructions: there are n plugs, m devices and K-type converters. Require the device to plug as much as possible, ask for a minimum number of mismatched devices.

Solution: to the reading of the various plug coding, source point to equipment, equipment through the converter to plug, plug to the meeting point each building a capacity of 1 side. The maximum number of matching devices can be obtained by running the Max stream at one time.

Note that this code in the magic of the place of the dead loop-to determine the queue is empty statement ... Σ (° °| | |) ︴ so we mainly look at the "line of thought"? :-)

1#include <cstdio>2#include <cstdlib>3#include <cstring>4#include <algorithm>5#include <iostream>6#include <queue>7 using namespacestd;8 9 Const intn= the, m= the, k= the;Ten Const intnn=310, mm=310, inf= (int) 1e9; One intN,m,k,ts,st,ed,len; A intD[nn],last[nn]; - Chars[n],ss[n],str[3*n][n];//, sb[m][n]; - structedge{intX,y,fl,next;} A[MM]; thequeue<int>Q; -  - intMmin (intXintY) {returnX<y?x:y;} - intget_id () + { -      for(intI=1; i<=ts;i++) +       if(!STRCMP (S,str[i]))returni; Astrcpy (str[++ts],s); at     returnts; - } - voidInsintXintYintFL) - { -A[++len].x=x,a[len].y=y,a[len].fl=FL; -a[len].next=last[x],last[x]=Len; inA[++len].x=y,a[len].y=x,a[len].fl=0; -a[len].next=last[y],last[y]=Len; to } + BOOLBFS () - { thememset (d,-1,sizeof(d)); *      while(!q.empty ()) Q.pop ();//The dead circle here??? -_-||| $Q.push (ST); d[st]=1;Panax Notoginseng      while(!q.empty ()) -     { the       intx=Q.front (); Q.pop (); +        for(intI=last[x];i;i=a[i].next) A       { the         inty=a[i].y; +         if(d[y]!=-1||! A[I].FL)Continue;//FL -d[y]=d[x]+1, Q.push (y); $         //if (y==ed) break;//No, this is for the 61st line of optimization. $       } -     } -     if(d[ed]==-1)return false; the     return true; - }Wuyi intDfsintXintflow) the { -     if(x==ed)returnflow; Wu     intsum=0; -      for(intI=last[x];i;i=a[i].next) About     { $       inty=a[i].y; -       if(d[y]!=d[x]+1||! A[I].FL)Continue;// -       intT=dfs (Y, Mmin (a[i].fl,flow-sum)); -A[i].fl-=t, a[i^1].fl+=T; Asum+=T; +       if(Sum==flow) Break; the     } -     if(sum==0) d[x]=-1;// $     returnsum; the } the intdinic () the { the     intsum=0; -      while(BFS ()) inSum+=dfs (St,inf);//The capacity at this point is INF the     returnsum; the } About intMain () the { the     intt,x,y; thescanf"%d",&T); +      while(t--) -     { thest=1, ed=2, len=1, ts=2;Bayiscanf"%d",&n); theMemset (Last,0,sizeof(last)); the        for(intI=1; i<=n;i++) -       { -scanf"%s", s); thex=get_id (); theIns (x,ed,1); the       } thescanf"%d",&m); -        for(intI=1; i<=m;i++) the       { thescanf"%s%s", s,s); thex=get_id ();94Ins (st,x,1); the       } thescanf"%d",&k); the        for(intI=1; i<=k;i++)98       { Aboutscanf"%s", s); -x=get_id ();101scanf"%s", s);102y=get_id ();103Ins (x, Y,1);104       } the       intans=dinic ();106       if(T) printf ("\ n");107printf"%d\n", M-ans);108     }109     return 0; the}

"UVA 753" A Plug for UNIX (graph theory-Maximum flow dinic)