POJ 2367 Genealogical Tree "topological sort"

Test instructions: It probably means--there is a family gathered together, now by the people inside the family to speak, generational high person first speech. Now give N, and then give the number of n row number I input means the number of descendants of line I, then these numbers are in the back of I.

Like Example 5

0

4 5 1 0

1 0

5 3 0

3 0

1 No number behind

2 followed by 4 5 1

3 followed by a 1

4 followed by 5 3

5 followed by a 3

A little experience of topological sort

(1) First save the diagram and then store the corresponding vertex degree

(2) Select a point without a precursor (i.e., a point with an entry level of 0) in the diagram and join the queue

(3) Delete the edge of the point at which it is starting (minus 1 of the points pointed to by the dot)

(4) Repeat the above operation until there are no points with an entry level of 0

#include <iostream>  #include <cstdio>  #include <cstring>  #include <algorithm>  using namespace Std;int iq,n;int queue[1000],map[1000][1000],indegree[1000];void toposort () {int i,j,k;iq=0;for ( i=1;i<=n;i++) {for (j=1;j<=n;j++) {if (map[i][j]) indegree[j]++;}} for (i=1;i<=n;i++) {for (j=1;j<=n;j++) {if (indegree[j]==0) {queue[iq++]=j;break;}} indegree[j]=-1;//this point into the after, the degree of this is recorded as-1, in order to avoid the next time it is added to the queue for (k=1;k<=n;k++) {if (map[j][k]) indegree[k]--;}} int main () {int i,v;scanf ("%d", &n), for (i=1;i<=n;i++) {while (scanf ("%d", &v)!=eof&&v) map[i][v]=1;} Toposort (); for (i=0;i<iq-1;i++) printf ("%d", Queue[i]);p rintf ("%d", Queue[i]);}

　　

The first question of topological sequencing [email protected][email protected]

Go--go

POJ 2367 Genealogical Tree "topological sort"