HDU 1285 determining the tournament position (basis for topological sorting)

Main topic:

The title is to give you an n-node, a forward-and-loop graph, and then, for this loop-free graph, we sort him out in topological order, making the sequence in the topological order output in dictionary order.

Problem Solving Ideas:

Apply Toposort () template directly ...

First talk about the meaning of Toposort ():

Topological sequencing that is, when we complete a project, the project is divided into a lot of sub-projects, we can not do a lot of work every time, we have to follow certain things

The internal link between the services to complete the project, such as you want to complete a project, then you must complete the B project, so that B priority is higher than a. So we have a map of the building.

Code:

1# include<cstdio>2# include<iostream>3# include<fstream>4# include<algorithm>5# include<functional>6# include<cstring>7# include<string>8# include<cstdlib>9# include<iomanip>Ten# include<numeric> One# include<cctype> A# include<cmath> -# include<ctime> -# include<queue> the# include<stack> -# include<list> -# include<Set> -# include<map> +  - using namespacestd; +  A Const DoublePi=4.0*atan (1.0); at  -typedefLong LongLL; -typedef unsignedLong LongULL; -  -# define INF999999999 -# define MAX521 in  - intEdge[max][max];//adjacency Matrix to intIndex[max]; + intBook[max]; - inttop; the intn,m; *  $ Panax Notoginseng voidInit () - { theMemset (Edge,0,sizeof(Edge)); +      for(inti =1; I <= n;i++ ) A     { theIndex[i] =0; +Book[i] =0; -     } $      for(inti =0; I < m;i++ ) $     { -         intt1,t2; -scanf"%d%d",&t1,&T2); the         if(Edge[t1][t2] = =0 ) -         {WuyiEDGE[T1][T2] =1; theindex[t2]++; -         } Wu     } - } About  $ voidToposort () - { -     intStep; -      while(Top <N) A     { +          for(inti =1; I <= n;i++ ) the         { -             if(index[i]==0&&book[i]==0 ) $             { theStep =i; the                  Break; the             } the         } -Book[step] =1; in         if(top) theprintf" "); theprintf"%d", step); About  thetop++; the          for(intj =1; J <= n;j++ ) the         { +             if(edge[step][j]==1 ) -             { theindex[j]--;Bayi             } the         } the  -     } -printf"\ n"); the } the  the intMainvoid) the { -      while(SCANF ("%d%d", &n,&m)! =EOF) the     { the init (); thetop =0;94 Toposort (); the     } the      the     return 0;98}

HDU 1285 determining the tournament position (basis for topological sorting)