拓扑排序模板

# include <stdio.h>
# include <string.h>
# define MAX 1000
int n,m,indegree[MAX];
int G[MAX][MAX],q[MAX];
void toposort()
{
    int i,j,k;
    for(i=0;i<n;) 
    {
        for(j=1;j<=n;j++) //从最小的点开始找。
        {
            if(indegree[j] == 0)
            {
                indegree[j]--;
                q[i++]=j;
                for(k=1;k<=n;k++)
                    if(G[j][k])
                        indegree[k]--;

            }
        }
    }
}
int main()
{
    int i,a,b;
    while(scanf("%d%d",&n,&m) == 2)
    {
        memset(G,0,sizeof(G));
        memset(indegree,0,sizeof(indegree));
        for(i=1;i<=m;i++)
        {
            scanf("%d%d",&a,&b);
            if(G[a][b] == 0)
            {
                G[a][b]=1;
                indegree[b]++;
            }
        }
        toposort();
        for(i=0;i<n;i++)
        {
            if(i != n-1)
                printf("%d ",q[i]);
            else 
                printf("%d",q[i]);
        }
        printf("\n");
    }
    return 0;
}