拓扑排序

•//拓扑排序,邻接阵形式,复杂度O(n^2)

•//如果无法完成排序,返回0,否则返回1,ret返回有序点列

•//传入图的大小n和邻接阵mat,不相邻点边权0

•#define MAXN 100

 

•int toposort(int n,int mat[][MAXN],int* ret){

•  int d[MAXN],i,j,k;

•  for (i=0;i<n;i++)

•  for (d[i]=j=0;j<n;d[i]+=mat[j++][i]);

•  for (k=0;k<n;ret[k++]=i){

•  for (i=0;d[i]&&i<n;i++);

•  if (i==n)

•  return 0;

•  for (d[i]=-1,j=0;j<n;j++)

•  d[j]-=mat[i][j];

•  }

•  return 1;

•}

 

------------------------------hdu 1258----------------------------------

•int main(int argc, char *argv[])

•{

•    int map[501][501];

•    int *p,data[501];

•    int m,n,p1,p2;

•    while(cin>>n>>m)

•    {

•    memset(map,0,sizeof(map));

•for(int i=1;i<=m;i++)

•    {

•            cin>>p1>>p2;

•            map[p1-1][p2-1]=1;

•   

•    }

•    p=data;

•    toposort(n,map,p);

•    for(int j=0;j<n-1;j++)

•    cout<<*(p+j)+1<<" ";

•    cout<<*(p+n-1)+1<<endl;

•   

•   }

•    system("PAUSE");

•    return EXIT_SUCCESS;

•}