public bool Search(PathSumLinkList.TreeNode node, int sum, int currentSum)
{
if (node == null) return false;
if (node.val < 0) return false;
if(node.left == null && node.right == null)
{
return node.val + currentSum == sum;
}
return Search(node.left, sum, node.val + currentSum) || Search(node.right, sum, node.val + currentSum);
}
public void PathSumTestNormalCase()
{
PathSum p = new PathSum();
PathSumLinkList l = new PathSumLinkList();
/*
* 5
* / \
* 4 8
* / / \
* 11 13 4
* / \ \
* 7 2 1
*/
int[] case1 = new int[] { 5, 4, 8, 11, 0, 13, 4, 7, 2, -1, -1, -1, -1, -1, 1 };
PathSumLinkList.TreeNode tree1 = new PathSumLinkList.TreeNode(5, 0);
l.GenerateTree(case1, ref tree1);
/*
* 0
* / \
* 0 8
* / / \
* 11 13 4
*/
int[] case2 = new int[] { 0, 0, 8, 11, 0, 13, 4 };
PathSumLinkList.TreeNode tree2 = new PathSumLinkList.TreeNode(0, 0);
l.GenerateTree(case2, ref tree2);
/*
* 1
* /
* 2
*/
int[] case3 = new int[] { 1, 2 };
PathSumLinkList.TreeNode tree3 = new PathSumLinkList.TreeNode(1, 0);
l.GenerateTree(case3, ref tree3);
Assert.AreEqual(true, p.HasPathSum(tree1, 22));
Assert.AreEqual(false, p.HasPathSum(tree1, 9));
Assert.AreEqual(false, p.HasPathSum(tree1, 20));
Assert.AreEqual(false, p.HasPathSum(tree1, 25));
Assert.AreEqual(true, p.HasPathSum(tree2, 0));
Assert.AreEqual(true, p.HasPathSum(tree2, 11));
Assert.AreEqual(true, p.HasPathSum(tree2, 21));
Assert.AreEqual(false, p.HasPathSum(tree2, 5));
Assert.AreEqual(true, p.HasPathSum(tree3, 3));
}
public bool HasPathSum(PathSumLinkList.TreeNode root, int sum)
{
return Search(root, sum, 0);
}