bool hasPathSum2(TreeNode *root, int sum) {
if (root==NULL) return false;
if (root->left==NULL && root->right==NULL ){
return (root->val==sum);
}
if (root->left){
root->left->val += root->val;
if (hasPathSum2(root->left, sum)){
return true;
}
}
if (root->right){
root->right->val += root->val;
if (hasPathSum2(root->right, sum)){
return true;
}
}
return false;
}
bool hasPathSum(TreeNode *root, int sum) {
// dfs version
return hasPathSum1(root, sum);
// bfs version
return hasPathSum2(root, sum);
}
bool hasPathSum(TreeNode *root, int sum) {
if (random()%2){
return hasPathSum1(root, sum);
}
return hasPathSum2(root, sum);
}
