leetCode/112.路径总和.html

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    <script>
      // 给你二叉树的根节点 root 和一个表示目标和的整数 targetSum ，判断该树中是否存在 根节点到叶子节点 的路径，这条路径上所有节点值相加等于目标和 targetSum 。

      // 叶子节点 是指没有子节点的节点。

      var hasPathSum = function (root, targetSum) {
        if (!root) return false;
        function addP(node, sum) {
          if (!node.left && !node.right) return sum === targetSum;
          let left = node.left ? addP(node.left, sum + node.left.val) : false;
          let right = node.right ? addP(node.right, sum + node.right.val) : false;
          return left || right;
        }
        return addP(root, root.val);
      };

      var hasPathSum = function (root, targetSum) {
        if (!root) return false;
        if (!root.right && !root.left) return root.val === targetSum;
        return hasPathSum(root.right, targetSum - root.val) || hasPathSum(root.left, targetSum - root.val);
      };

      //  3
      //  / \
      // 9  20
      //   /  \
      //  15   7
      let root = {
        val: 3,
        left: {
          val: 9
        },
        right: {
          val: 20,
          left: {
            val: 15
          },
          right: {
            val: 7
          }
        }
      };
      console.log('hasPathSum 12 true = ', hasPathSum(root, 12));
      console.log('hasPathSum 13 false = ', hasPathSum(root, 13));
      console.log('hasPathSum 29 false = ', hasPathSum(root, 29));
      console.log('hasPathSum 30 true = ', hasPathSum(root, 30));
    </script>
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