|
马上注册,结交更多好友,享用更多功能^_^
您需要 登录 才可以下载或查看,没有账号?立即注册
x
传送门:https://pintia.cn/problem-sets/9 ... /994805365537882112
解:
二叉树的遍历
- #include<cstdio>
- #include<cstring>
- #include<queue>
- using namespace std;
- typedef struct node{
- int lchild, rchild;
- } BTNode;
- int ttl;
- void reverse_tree(int root, BTNode tree[])
- {
- if (root == -1) return;
- reverse_tree(tree[root].lchild, tree);
- reverse_tree(tree[root].rchild, tree);
-
- int temp = tree[root].lchild;
- tree[root].lchild = tree[root].rchild;
- tree[root].rchild = temp;
- }
- void BFS(int root, BTNode tree[])
- {
- queue<int> q;
- q.push(root);
- while (!q.empty())
- {
- int index = q.front();
- q.pop();
- printf("%d", index);
- if (--ttl) putchar(' ');
- if (tree[index].lchild != -1) q.push(tree[index].lchild);
- if (tree[index].rchild != -1) q.push(tree[index].rchild);
- }
- putchar('\n');
- }
- void print_inorder(int root, BTNode tree[])
- {
- if (root == -1) return;
- print_inorder(tree[root].lchild, tree);
- printf("%d", root);
- if (--ttl) putchar(' ');
- print_inorder(tree[root].rchild, tree);
- }
- int main(void)
- {
- int n, hash_table[15] = {0};
- BTNode tree[15];
- memset(tree, -1, sizeof(tree));
-
- scanf("%d", &n);
- if (!n) return 0;
- getchar();
- for (int i = 0; i < n; i++)
- {
- char s[5];
- fgets(s, 5, stdin);
- if (s[0] != '-') ++hash_table[tree[i].lchild = s[0] - '0'];
- if (s[2] != '-') ++hash_table[tree[i].rchild = s[2] - '0'];
- }
- for (int i = 0; i < n; i++)
- if (!hash_table[i])
- {
- reverse_tree(i, tree);
- ttl = n;
- BFS(i, tree);
- ttl = n;
- print_inorder(i, tree);
- break;
- }
- return 0;
- }
复制代码 |
|