Leetcode 112.路徑總和：遞歸函數(shù)沒(méi)有返回值也是可以的（leetcode 8ms）

class?Solution?{

public:

????bool?hasPath?=?false; // 定義一個(gè)全局結(jié)果變量

????void?backtracking(TreeNode*?root,?int?pathSum,?int?targetSum)?{

????????if?(hasPath)?return; // 如果已經(jīng)找到 不在繼續(xù)遞歸遍歷

????????if?(!root->left?&&?!root->right)?{

????????????if?(pathSum?==?targetSum)?hasPath?=?true;

????????????return;

????????}

????????if?(root->left)?{

????????????pathSum?+=?root->left->val;

????????????backtracking(root->left,?pathSum,?targetSum);

????????????pathSum?-=?root->left->val;

????????}

????????if?(root->right)?{

????????????pathSum?+=?root->right->val;

????????????backtracking(root->right,?pathSum,?targetSum);

????????????pathSum?-=?root->right->val;

????????}

????}

????bool?hasPathSum(TreeNode*?root,?int?targetSum)?{

????????if?(!root)?return?false;

????????backtracking(root,?root->val,?targetSum);

????????return?hasPath; // 返回結(jié)果

????}

};