Problem p02280 (C++) — buggy submission, verdict: Runtime Error

#include <cstdio>
#define MAX 10000
#define NIL -1

struct Node {
  int parent, left, right;
};

Node T[MAX];
int n, D[MAX], H[MAX];

void setDepth(int u, int d) {
  if (u == NIL)
    return;
  D[u] = d;
  setDepth(T[u].left, d + 1);
  setDepth(T[u].right, d + 1);
}

int setHeight(int u) {
  int h1 = 0, h2 = 0;
  if (T[u].left != NIL)
    h1 = setHeight(T[u].left) + 1;
  if (T[u].right != NIL)
    h2 = setHeight(T[u].right) + 1;
  return H[u] = (h1 > h2 ? h1 : h2);
}

int getSibling(int u) {
  if (T[u].parent == NIL)
    return NIL;
  if (T[T[u].parent].left != u && T[T[u].parent].left != NIL)
    return T[T[u].parent].left;
  if (T[T[u].parent].right != u && T[T[u].parent].right != NIL)
    return T[T[u].parent].right;
  return NIL;
}

void print(int u) {
  printf("node %d: ", u);
  printf("parent = %d, ", T[u].parent);
  printf("sibling = %d, ", getSibling(u));
  int deg = 0;
  if (T[u].left != NIL)
    deg++;
  if (T[u].right != NIL)
    deg++;
  printf("degree = %d, ", deg);
  printf("depth = %d, ", D[u]);
  printf("height = %d, ", H[u]);

  if (T[u].parent == NIL) {
    printf("root\\n");
  } else if (T[u].left == NIL && T[u].right == NIL) {
    printf("leaf\\n");
  } else {
    printf("internal node\\n");
  }
}

int main() {

  int v, l, r, root = 0;
  scanf("%d", &n);
  for (int i = 0; i < n; i++)
    T[i].parent = NIL;

  for (int i = 0; i < n; i++) {
    scanf("%d %d %d", &v, &l, &r);
    T[v].left = l;
    T[v].right = r;
    if (l != NIL)
      T[l].parent = v;
    if (r != NIL)
      T[r].parent = v;
  }

  for (int i = 0; i < n; i++)
    if (T[i].parent == NIL)
      root = i;

  setDepth(root, 0);
  setHeight(root);

  for (int i = 0; i < n; i++)
    print(i);

  return 0;
}

Error: 0

Fixed submission:

#include <cstdio>
#define MAX 10000
#define NIL -1

struct Node {
  int parent, left, right;
};

Node T[MAX];
int n, D[MAX], H[MAX];

void setDepth(int u, int d) {
  if (u == NIL)
    return;
  D[u] = d;
  setDepth(T[u].left, d + 1);
  setDepth(T[u].right, d + 1);
}

int setHeight(int u) {
  int h1 = 0, h2 = 0;
  if (T[u].left != NIL)
    h1 = setHeight(T[u].left) + 1;
  if (T[u].left != NIL)
    h2 = setHeight(T[u].right) + 1;
  return H[u] = (h1 > h2 ? h1 : h2);
}

int getSibling(int u) {
  if (T[u].parent == NIL)
    return NIL;
  if (T[T[u].parent].left != u && T[T[u].parent].left != NIL)
    return T[T[u].parent].left;
  if (T[T[u].parent].right != u && T[T[u].parent].right != NIL)
    return T[T[u].parent].right;
  return NIL;
}

void print(int u) {
  printf("node %d: ", u);
  printf("parent = %d, ", T[u].parent);
  printf("sibling = %d, ", getSibling(u));
  int deg = 0;
  if (T[u].left != NIL)
    deg++;
  if (T[u].right != NIL)
    deg++;
  printf("degree = %d, ", deg);
  printf("depth = %d, ", D[u]);
  printf("height = %d, ", H[u]);

  if (T[u].parent == NIL) {
    printf("root\\n");
  } else if (T[u].left == NIL && T[u].right == NIL) {
    printf("leaf\\n");
  } else {
    printf("internal node\\n");
  }
}

int main() {

  int v, l, r, root = 0;
  scanf("%d", &n);
  for (int i = 0; i < n; i++)
    T[i].parent = NIL;

  for (int i = 0; i < n; i++) {
    scanf("%d %d %d", &v, &l, &r);
    T[v].left = l;
    T[v].right = r;
    if (l != NIL)
      T[l].parent = v;
    if (r != NIL)
      T[r].parent = v;
  }

  for (int i = 0; i < n; i++)
    if (T[i].parent == NIL)
      root = i;

  setDepth(root, 0);
  setHeight(root);

  for (int i = 0; i < n; i++)
    print(i);

  return 0;
}