void binaryTreePathsDFS(TreeNode *curNode, vector<TreeNode *> &path, vector<string> &res) {
// terminating condition
if (curNode->left == NULL && curNode->right == NULL) {
// convert path into string
string s = "";
int i;
for (i = 0; i < path.size()-1; i++) {
s += to_string(path[i]->val) + "->";
}
s += to_string(path[i]->val);
res.push_back(s);
return;
}
// DFS step
if (curNode->left) {
path.push_back(curNode->left);
binaryTreePathsDFS(curNode->left, path, res);
path.pop_back();
}
if (curNode->right) {
path.push_back(curNode->right);
binaryTreePathsDFS(curNode->right, path, res);
path.pop_back();
}
}
//depth first travers
void binaryTreePathsDFS(TreeNode *root, string out, vector<string> &paths) {
if (!root->left && !root->right) paths.push_back(out);
if (root->left) {
binaryTreePathsDFS(root->left, out + "->" + to_string(root->left->val), paths);
}
if (root->right) {
binaryTreePathsDFS(root->right, out + "->" + to_string(root->right->val), paths);
}
}
vector<string> binaryTreePaths(TreeNode* root) {
vector<string> res;
if (!root) return res;
vector<TreeNode *> path;
path.push_back(root);
binaryTreePathsDFS(root, path, res);
return res;
}
vector<string> binaryTreePaths(TreeNode* root) {
vector<string> paths;
if (!root)
return paths;
binaryTreePathsDFS(root, to_string(root->val), paths);
return paths;
}
