1. 二叉树中和为某一值的路径

路径：从树的根节点到叶子节点经过的节点形成的路径，例如途中（10，5，4），（10，5，7），（10，12）

满足和为22的路径有（10，5，7）、（10，12）

 

参考代码

void FindPath(TreeNode *root, vector
     
       &vec, int cur, int aim){    if (root == NULL)        return;    vec.push_back(*root);    cur += root->val;    bool IsLeft = ((root->left == NULL) && (root->right == NULL));    if (cur == aim && IsLeft)    {        for (vector
      
       ::iterator beg = vec.begin(); beg != vec.end(); ++beg)            cout << beg->val << " ";        cout << endl;    }    if (root->left != NULL)        FindPath(root->left, vec, cur, aim);    if (root->right != NULL)        FindPath(root->right, vec, cur, aim);    vec.pop_back();}void FindPath(TreeNode *root, int aim){    if (root == NULL)        return;    vector
       
         vec;    FindPath(root, vec, 0, aim);}
       
      
     

测试

#include 
      
       #include 
       
        using namespace std;struct TreeNode {    int val;    TreeNode *left;    TreeNode *right;    TreeNode(int v) : val(v), left(NULL), right(NULL) {};};void FindPath(TreeNode *root, vector
        
          &vec, int cur, int aim){    if (root == NULL)        return;    vec.push_back(*root);    cur += root->val;    bool IsLeft = ((root->left == NULL) && (root->right == NULL));    if (cur == aim && IsLeft)    {        for (vector
         
          ::iterator beg = vec.begin(); beg != vec.end(); ++beg)            cout << beg->val << " ";        cout << endl;    }    if (root->left != NULL)        FindPath(root->left, vec, cur, aim);    if (root->right != NULL)        FindPath(root->right, vec, cur, aim);    vec.pop_back();}void FindPath(TreeNode *root, int aim){    if (root == NULL)        return;    vector
          
            vec;    FindPath(root, vec, 0, aim);}int main(){    TreeNode *root = new TreeNode(10);    TreeNode *p1 = new TreeNode(5);    TreeNode *p2 = new TreeNode(12);    TreeNode *p3 = new TreeNode(4);    TreeNode *p4 = new TreeNode(7);    root->left = p1;    root->right = p2;    p1->left = p3;    p1->right = p4;    FindPath(root, 22);}