/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode() : val(0), left(nullptr), right(nullptr) {}
* TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
* TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
* };
*/
class Solution {
public:
typedef long long LL;
int cnt=0;
void dfs_cnt(TreeNode* u,int tar,LL s)
{
if(!u) return;
s+=u->val;
dfs_cnt(u->left,tar,s);
dfs_cnt(u->right,tar,s);
if(s==tar) cnt++;
return;
}
void dfs(TreeNode* u,int tar)
{
if(!u) return;
dfs_cnt(u,tar,0);
dfs(u->left,tar);
dfs(u->right,tar);
}
int pathSum(TreeNode* root, int targetSum) {
dfs(root,targetSum);
return cnt;
}
};
Leetcode437. 路径总和 III
发布时间 2023-07-26 12:01:57作者: 穿过雾的阴霾