LeetCode-437-路径总和III
思路
判断以当前根节点为起点,再以左右节点为起点遍历即可
代码
class Solution {
int cnt=0;
public int pathSum(TreeNode root, int targetSum) {
if(root==null)return 0;
getSum(root,targetSum);
pathSum(root.left,targetSum);
pathSum(root.right,targetSum);
return cnt;
}
public void getSum(TreeNode root,int targetSum){
if(root==null)return;
if(targetSum==root.val)cnt++;
getSum(root.left,targetSum-root.val);
getSum(root.right,targetSum-root.val);
}
}