Given a binary tree containing digits from 0-9 only,
each root-to-leaf path could represent a number.
An example is the root-to-leaf path 1->2->3 which
represents the number 123.
Find the total sum of all root-to-leaf numbers.
For example,
1 / 2 3
The root-to-leaf path 1->2 represents
the number 12.
The root-to-leaf path 1->3 represents
the number 13.
Return the sum = 12 + 13 = 25.
void helper_leaf(BinTree* root,vector<int>& path,int& sum)
{
if(root == NULL)
return ;
path.push_back(root->value);
if(root->left == NULL && root->right == NULL)
{
int tmp=0;
for(int i=0;i<path.size();i++)
tmp = tmp*10 + path[i];
sum += tmp;
// cout<<"tmp is "<<tmp<<endl;
//return ;
}
helper_leaf(root->left,path,sum);
helper_leaf(root->right,path,sum);
path.pop_back();
}
int RootToLeaf(BinTree* root)
{
if(root == NULL)
return 0;
vector<int> path;
int sum=0;
helper_leaf(root,path,sum);
return sum;
}
Sum Root to Leaf Numbers--LeetCode
原文地址：http://blog.csdn.net/yusiguyuan/article/details/44957589
