题目一：

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.

/**
 * Definition for binary tree
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution {
public:
    int sumNumbers(TreeNode *root)
	{
        if (root==NULL)
        {
			return 0;
        }
		int value = http://www.mamicode.com/0;>
题目二：
Given an unsorted array of integers, find the length of the longest consecutive elements sequence.
For example,
Given [100, 4, 200, 1, 3, 2],
The longest consecutive elements sequence is [1, 2, 3, 4]. Return its length: 4.
Your algorithm should run in O(n) complexity.
代码：
class Solution {
public:
int longestConsecutive(vector<int> &num) 
{
if(num.empty())
{
return 0;
}
int size = num.size();
sort(num.begin(),num.end());
int precount = 1;
int curcount = 1;
for(int i = 1;i<size;i++)
{
if(num[i]==num[i-1]+1)
{
curcount++;
}
else  if (num[i]!=num[i-1])
{
if (curcount>precount)
{
precount = curcount;
}
curcount = 1;
}
}
if(precount>curcount)
{
curcount = precount;
}
return curcount;
}
};