1004_Counting Leaves (30分)[bfs/dfs]

Posted 2021-03-20 niboss

bfs:记录层序

 1 #include<iostream>
 2 #include<vector>
 3 #include<queue>
 4 #include<map>
 5 #include<set>
 6 #include<cmath>
 7 #include<cstdio>
 8 #include<cstdlib>
 9 #include<cstring>
10 #include<algorithm>
11 using namespace std;
12 
13 const int maxSize = 500 + 10;
14 int N, M, K, Root, vRoot, maxLevel;
15 vector<int> nodes[maxSize];
16 int level[maxSize], book[maxSize];
17 
18 void bfs() {
19     level[1] = 0; //默认1号为根节点,其处在第0层
20     maxLevel = 0; //输出范围(树的层数)
21     queue<int> que;
22     que.push(1);
23     while (!que.empty()) {
24         int v = que.front();
25         que.pop();
26         if (nodes[v].size() == 0) book[level[v]]++; //该节点无子节点
27         for (int i = 0; i < nodes[v].size(); i++) { //该节点有子节点
28             que.push(nodes[v][i]);
29             level[nodes[v][i]] = level[v] + 1; //标志子节点的层数
30         }
31         maxLevel = max(maxLevel, level[v]);
32     }
33 }
34 
35 int main()
36 {
37     while (cin >> N >> M) {
38         memset(nodes, 0, sizeof(nodes));
39         memset(level, 0, sizeof(level));
40         memset(book, 0, sizeof(book));
41         for (int i = 0; i < M; i++) {
42             cin >> Root >> K;
43             for (int j = 0; j < K; j++) {
44                 cin >> vRoot;
45                 nodes[Root].push_back(vRoot);
46             }
47         }
48         bfs();
49         cout << book[0];
50         for (int i = 1; i <= maxLevel; i++) {
51             cout << " " << book[i];
52         }
53         cout << endl;
54     }
55     return 0;
56 }

 

dfs:

 1 #include<iostream>
 2 #include<vector>
 3 #include<queue>
 4 #include<map>
 5 #include<set>
 6 #include<cmath>
 7 #include<cstdio>
 8 #include<cstdlib>
 9 #include<cstring>
10 #include<algorithm>
11 using namespace std;
12 
13 const int maxSize = 500 + 10;
14 int N, M, K, Root, vRoot, maxLevel;
15 vector<int> nodes[maxSize];
16 int book[maxSize];
17 
18 void dfs(int root,int level) {
19     if (nodes[root].size() == 0) {
20         book[level]++;
21         maxLevel = max(maxLevel, level);
22         return;
23     }
24     for (int i = 0; i < nodes[root].size(); i++) {
25         dfs(nodes[root][i], level + 1);
26     }
27 }
28 
29 int main()
30 {
31     while (cin >> N >> M) {
32         memset(nodes, 0, sizeof(nodes));
33         memset(book, 0, sizeof(book));
34         for (int i = 0; i < M; i++) { //关联表建树
35             cin >> Root >> K;
36             for (int j = 0; j < K; j++) {
37                 cin >> vRoot;
38                 nodes[Root].push_back(vRoot);
39             }
40         }
41         maxLevel = 0;
42         dfs(1,0); //根节点1,为第0层
43         cout << book[0];
44         for (int i = 1; i <= maxLevel; i++) {
45             cout << " " << book[i];
46         }
47         cout << endl;
48     }
49     return 0;
50 }