标签：class tput amp || junit java sid new t ret
100. Same Tree
Given two binary trees, write a function to check if they are the same or not.
Two binary trees are considered the same if they are structurally identical and the nodes have the same value.
Example 1:
Input: 1 1
/ \ / 2 3 2 3
[1,2,3], [1,2,3]
Output: true
Example 2:
Input: 1 1
/ 2 2
[1,2], [1,null,2]
Output: false
Example 3:
Input: 1 1
/ \ / 2 1 1 2
[1,2,1], [1,1,2]
Output: false
package leetcode.easy;
import java.util.ArrayDeque;
/**
* Definition for a binary tree node. public class TreeNode { int val; TreeNode
* left; TreeNode right; TreeNode(int x) { val = x; } }
*/
class TreeNode {
int val;
TreeNode left;
TreeNode right;
TreeNode(int x) {
val = x;
}
}
public class SameTree {
@org.junit.Test
public void test1() {
TreeNode tn11 = new TreeNode(1);
TreeNode tn12 = new TreeNode(2);
TreeNode tn13 = new TreeNode(3);
tn11.left = tn12;
tn11.right = tn13;
tn12.left = null;
tn12.right = null;
tn13.left = null;
tn13.right = null;
TreeNode tn21 = new TreeNode(1);
TreeNode tn22 = new TreeNode(2);
TreeNode tn23 = new TreeNode(3);
tn21.left = tn22;
tn21.right = tn23;
tn22.left = null;
tn22.right = null;
tn23.left = null;
tn23.right = null;
System.out.println(isSameTree1(tn11, tn21));
System.out.println(isSameTree2(tn11, tn21));
}
@org.junit.Test
public void test2() {
TreeNode tn11 = new TreeNode(1);
TreeNode tn12 = new TreeNode(2);
tn11.left = tn12;
tn11.right = null;
tn12.left = null;
tn12.right = null;
TreeNode tn21 = new TreeNode(1);
TreeNode tn22 = new TreeNode(2);
tn21.left = null;
tn21.right = tn22;
tn22.left = null;
tn22.right = null;
System.out.println(isSameTree1(tn11, tn21));
System.out.println(isSameTree2(tn11, tn21));
}
@org.junit.Test
public void test3() {
TreeNode tn11 = new TreeNode(1);
TreeNode tn12 = new TreeNode(2);
TreeNode tn13 = new TreeNode(1);
tn11.left = tn12;
tn11.right = tn13;
tn12.left = null;
tn12.right = null;
tn13.left = null;
tn13.right = null;
TreeNode tn21 = new TreeNode(1);
TreeNode tn22 = new TreeNode(1);
TreeNode tn23 = new TreeNode(2);
tn21.left = tn22;
tn21.right = tn23;
tn22.left = null;
tn22.right = null;
tn23.left = null;
tn23.right = null;
System.out.println(isSameTree1(tn11, tn21));
System.out.println(isSameTree2(tn11, tn21));
}
public boolean isSameTree1(TreeNode p, TreeNode q) {
// p and q are both null
if (p == null && q == null) {
return true;
}
// one of p and q is null
if (q == null || p == null) {
return false;
}
if (p.val != q.val) {
return false;
}
return isSameTree1(p.right, q.right) && isSameTree1(p.left, q.left);
}
public boolean check(TreeNode p, TreeNode q) {
// p and q are null
if (p == null && q == null) {
return true;
}
// one of p and q is null
if (q == null || p == null) {
return false;
}
if (p.val != q.val) {
return false;
}
return true;
}
public boolean isSameTree2(TreeNode p, TreeNode q) {
if (p == null && q == null) {
return true;
}
if (!check(p, q)) {
return false;
}
// init deques
ArrayDeque<TreeNode> deqP = new ArrayDeque<TreeNode>();
ArrayDeque<TreeNode> deqQ = new ArrayDeque<TreeNode>();
deqP.addLast(p);
deqQ.addLast(q);
while (!deqP.isEmpty()) {
p = deqP.removeFirst();
q = deqQ.removeFirst();
if (!check(p, q)) {
return false;
}
if (p != null) {
// in Java nulls are not allowed in Deque
if (!check(p.left, q.left)) {
return false;
}
if (p.left != null) {
deqP.addLast(p.left);
deqQ.addLast(q.left);
}
if (!check(p.right, q.right)) {
return false;
}
if (p.right != null) {
deqP.addLast(p.right);
deqQ.addLast(q.right);
}
}
}
return true;
}
}
标签：class tput amp || junit java sid new t ret
原文地址：https://www.cnblogs.com/denggelin/p/11601193.html
