Path Sum III

題意：

解題思路：

public class Solution{
    public void findSum(TreeNode node, int sum, int[] path, int level) {
        if (node == null) {
            return;
        }

        path[level] = node.data;

        int t = 0;
        for (int i = level; i >= 0; i--) {
            t += path[i];
            if (t == sum) {
                print(path, i, level);
            }
        }

        findSum(node.left, sum, path, level + 1);
        findSum(node.right, sum, path, level + 1);

        path[level] = Integer.MIN_VALUE;
    }

    public void findSum(TreeNode node, int sum) {
        int depth = depth(node);
        int[] path = new int[depth];
        findSum(node, sum, path, 0);
    }

    public static void print(int[] path, int start, int end) {
        for (int i = start, i <= end; i++) {
            System.outprintln(path[i] + " ");
        }
        System.out.println();
    }

    public int depth(TreeNode node) {
        if (node == null) {
            return 0;
        } else {
            return 1 + Math.max(depth(node.left), depth(node.right));
        }
    }
}