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package class14;
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// 本题测试链接 : https://www.nowcoder.com/practice/e13bceaca5b14860b83cbcc4912c5d4a
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// 请同学们务必参考如下代码中关于输入、输出的处理
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// 这是输入输出处理效率很高的写法
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// 提交以下所有代码，并把主类名改成Main
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// 可以直接通过
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import java.io.BufferedReader;
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import java.io.IOException;
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import java.io.InputStreamReader;
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import java.io.OutputStreamWriter;
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import java.io.PrintWriter;
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import java.io.StreamTokenizer;
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public class Code03_BiggestBSTTopologyInTree {
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public static void main(String[] args) throws IOException {
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BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
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StreamTokenizer in = new StreamTokenizer(br);
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PrintWriter out = new PrintWriter(new OutputStreamWriter(System.out));
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while (in.nextToken() != StreamTokenizer.TT_EOF) {
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int n = (int) in.nval;
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in.nextToken();
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int h = (int) in.nval;
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int[][] tree = new int[n + 1][3];
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for (int i = 1; i <= n; i++) {
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in.nextToken();
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int c = (int) in.nval;
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in.nextToken();
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int l = (int) in.nval;
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in.nextToken();
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int r = (int) in.nval;
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tree[l][0] = c;
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tree[r][0] = c;
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tree[c][1] = l;
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tree[c][2] = r;
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}
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out.println(maxBSTTopology(h, tree, new int[n + 1]));
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out.flush();
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}
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}
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// h: 代表当前的头节点
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// t: 代表树 t[i][0]是i节点的父节点、t[i][1]是i节点的左孩子、t[i][2]是i节点的右孩子
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// m: i节点为头的最大bst拓扑结构大小 -> m[i]
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// 返回: 以h为头的整棵树上，最大bst拓扑结构的大小
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public static int maxBSTTopology(int h, int[][] t, int[] m) {
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if (h == 0) {
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return 0;
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}
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int l = t[h][1];
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int r = t[h][2];
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int c = 0;
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int p1 = maxBSTTopology(l, t, m);
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int p2 = maxBSTTopology(r, t, m);
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while (l < h && m[l] != 0) {
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l = t[l][2];
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}
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if (m[l] != 0) {
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c = m[l];
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while (l != h) {
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m[l] -= c;
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l = t[l][0];
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}
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}
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while (r > h && m[r] != 0) {
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r = t[r][1];
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}
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if (m[r] != 0) {
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c = m[r];
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while (r != h) {
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m[r] -= c;
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r = t[r][0];
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}
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}
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m[h] = m[t[h][1]] + m[t[h][2]] + 1;
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return Math.max(Math.max(p1, p2), m[h]);
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}
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}
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