拓撲排序是最直接的算法.
1 /* 拓撲排序 */
2
3 #include<iostream>
4 #include<vector>
5 using namespace std;
6 const int MAXN=120;
7 vector<int> adj[MAXN];
8
9 int into[MAXN];
10
11 int main()
12 {
13 //freopen("data.in","r",stdin);
14 //freopen("data.out","w",stdout);
15 int n;
16 memset(into,0,sizeof(into));
17 cin >> n;
18 for (int i=1;i<=n;++i)
19 {
20 int x;
21 cin >> x;
22 while (x!=0)
23 {
24 adj[i].push_back(x);
25 ++into[x];
26 cin >> x;
27 }
28 }
29 //for (int i=1;i<=n;++i) cout << into[i] << ' '; cout << endl;
30 bool everp=0;
31 for (int k=0;k<n;++k)
32 {
33 int i=1;
34 for (;i<=n;i++) if (!into[i]) break;
35 (everp) ? cout << ' ' << i : cout << i;
36 everp=1;
37 --into[i];
38 for (int j=0;j<adj[i].size();++j) --into[ adj[i][j] ];
39 }
40 cout << endl;
41 return 0;
42 }
43