简单ｄｆｓ 往孩子方向搜一遍 父母方向搜一遍 输入还搞什么字符串。。
1 #include <iostream> 2 #include<cstdio> 3 #include<cstring> 4 #include<algorithm> 5 #include<cstdlib> 6 #include<vector> 7 using namespace std; 8 vector<int>fa[1010]; 9 vector<int>ch[1010]; 10 int u,v,q[1010]; 11 int w[1010],vis1[1010],vis2[1010],o; 12 void dfs1(int u) 13 { 14 int i; 15 for(i = 0 ; i < (int)fa[u].size() ; i++) 16 { 17 int v = fa[u][i]; 18 if(!vis1[v]) 19 { 20 vis1[v] = 1; 21 dfs1(v); 22 } 23 } 24 } 25 void dfs2(int u) 26 { 27 int i; 28 for(i = 0 ; i < (int)ch[u].size() ; i++) 29 { 30 int v = ch[u][i]; 31 if(!vis2[v]) 32 { 33 vis2[v] = 1; 34 dfs2(v); 35 } 36 } 37 } 38 int main() 39 { 40 int i,j,n; 41 char s1[20],s2[20]; 42 scanf("%d",&n); 43 while(cin>>s1) 44 { 45 if(strcmp(s1,"BLOOD")==0) 46 break; 47 cin>>s2; 48 u = atoi(s1); 49 v = atoi(s2); 50 fa[u].push_back(v); 51 ch[v].push_back(u); 52 } 53 int g = 0; 54 while(scanf("%d",&j)!=EOF) 55 { 56 g++; 57 q[g] = j; 58 } 59 for(i = 1; i <= g ; i++) 60 { 61 if(!vis1[q[i]]) 62 { 63 vis1[q[i]] = 1; 64 dfs1(q[i]); 65 } 66 } 67 for(i = 1; i <= g ; i++) 68 { 69 if(!vis2[q[i]]) 70 { 71 vis2[q[i]] = 1; 72 dfs2(q[i]); 73 } 74 } 75 for(i = 1; i <= n ;i++) 76 if(!vis2[i]&&!vis1[i]) 77 { 78 o++; 79 w[o] = i; 80 } 81 if(!o) 82 printf("0 "); 83 else 84 { 85 for(i = 1; i < o ; i++) 86 printf("%d ",w[i]); 87 printf("%d ",w[o]); 88 } 89 return 0; 90 }