Open
Description
bfs
/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode(int x) : val(x), left(NULL), right(NULL) {}
* };
*/
class Solution {
public:
vector<int> rightSideView(TreeNode* root) {
vector<int> v;
queue<TreeNode*> q;
if(root == nullptr) return v;
q.push(root);
TreeNode* t;
while(!q.empty()){
auto n = q.size();
for(int i = 0; i < n; i++){
t = q.front();
if(t->left != nullptr){
q.push(t->left);
}
if(t->right != nullptr){
q.push(t->right);
}
q.pop();
}
v.push_back(t->val);
}
return v;
}
};
dfs
/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode(int x) : val(x), left(NULL), right(NULL) {}
* };
*/
class Solution {
public:
void dfs(TreeNode* root, int d, vector<int>& v){
if(root != nullptr){
if(v.size() == d) v.push_back(root->val);
else v[d] = root->val;
dfs(root->left, d + 1, v);
dfs(root->right, d + 1, v);
}
}
vector<int> rightSideView(TreeNode* root) {
vector<int> v;
dfs(root, 0, v);
return v;
}
};