题目链接： https://hihocoder.com/contest/offers53/problem/1
解题思路： 仔细阅读继承的规则，对照样例，就可以看出是一个前序遍历， 但是需要根据时间顺序指定遍历子节点的顺序，存储的时候按顺序存就可以了。然后把dead的人删掉。
1 #include <bits/stdc++.h> 2 using namespace std; 3 4 const int imax_n = 100005; 5 6 struct Edge 7 { 8 int u, v; 9 Edge() 10 { 11 12 } 13 }; 14 15 map<string, int> mp; 16 map<int, string> names; 17 int dead[imax_n]; 18 string king_name; 19 int cnt_name; 20 int n; 21 22 int head[imax_n]; 23 Edge edge[imax_n]; 24 int next_edge[imax_n]; 25 int cnt; 26 27 28 29 void init() 30 { 31 memset(head, -1, sizeof(head)); 32 memset(next_edge, -1, sizeof(next_edge)); 33 memset(dead, 0, sizeof(dead)); 34 cnt = 0; 35 mp.clear(); 36 names.clear(); 37 cnt_name = 0; 38 } 39 40 void addEdge(int u, int v) 41 { 42 edge[cnt].u = u; 43 edge[cnt].v = v; 44 next_edge[cnt] = head[u]; 45 head[u] = cnt++; 46 } 47 48 void dfs(int u) 49 { 50 if (dead[u] == 0 && names[u] != king_name) 51 { 52 cout<<names[u]<<endl; 53 } 54 stack<int> S; 55 for (int i = head[u]; i != -1; i = next_edge[i]) 56 { 57 S.push(edge[i].v); 58 } 59 while (!S.empty()) 60 { 61 int v = S.top(); 62 S.pop(); 63 dfs(v); 64 } 65 } 66 67 int main() 68 { 69 init(); 70 scanf("%d", &n); 71 cin>>king_name; 72 mp[king_name] = 1; 73 names[1] = king_name; 74 cnt_name = 2; 75 string op, father, son; 76 int u, v; 77 for (int i = 0; i < n; ++i) 78 { 79 cin>>op; 80 if (op.compare("birth") == 0) 81 cin>>father>>son; 82 else 83 { 84 cin>>father; 85 dead[mp[father]] = 1; 86 continue; 87 } 88 if (mp.find(father)==mp.end()) 89 { 90 mp[father] = cnt_name; 91 names[cnt_name++] = father; 92 } 93 if (mp.find(son) == mp.end()) 94 { 95 mp[son] = cnt_name; 96 names[cnt_name++] = son; 97 } 98 u = mp[father]; 99 v = mp[son]; 100 addEdge(u, v); 101 } 102 dfs(1); 103 return 0; 104 }