msb-public-java
/
LeetCode
mirror of https://github.com/yuanguangxin/LeetCode
1
2
Code Issues Projects Releases Wiki Activity

add q23/q101

Browse Source
pull/6/head
yuanguangxin 5 years ago
parent 832b75721a
commit ecfdf79e28
9 changed files with 299 additions and 44 deletions
Show Stats Download Patch File Download Diff File

112
.idea/workspace.xml
Unescape View File

@ -2,7 +2,14 @@
<project version="4"> <project version="4">
<component name="ChangeListManager"> <component name="ChangeListManager">
<list default="true" id="af7ffdf2-4ddc-4ed6-8222-60ed5acbc2ed" name="Default Changelist" comment=""> <list default="true" id="af7ffdf2-4ddc-4ed6-8222-60ed5acbc2ed" name="Default Changelist" comment="">
<change afterPath="$PROJECT_DIR$/src/q54/Solution.java" afterDir="false" /> <change afterPath="$PROJECT_DIR$/src/q101/f1/Solution.java" afterDir="false" />
<change afterPath="$PROJECT_DIR$/src/q101/f1/TreeNode.java" afterDir="false" />
<change afterPath="$PROJECT_DIR$/src/q101/f2/Solution.java" afterDir="false" />
<change afterPath="$PROJECT_DIR$/src/q101/f2/TreeNode.java" afterDir="false" />
<change afterPath="$PROJECT_DIR$/src/q101/f3/Solution.java" afterDir="false" />
<change afterPath="$PROJECT_DIR$/src/q101/f3/TreeNode.java" afterDir="false" />
<change afterPath="$PROJECT_DIR$/src/q23/ListNode.java" afterDir="false" />
<change afterPath="$PROJECT_DIR$/src/q23/Solution.java" afterDir="false" />
<change beforePath="$PROJECT_DIR$/.idea/workspace.xml" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/workspace.xml" afterDir="false" /> <change beforePath="$PROJECT_DIR$/.idea/workspace.xml" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/workspace.xml" afterDir="false" />
</list> </list>
<option name="SHOW_DIALOG" value="false" /> <option name="SHOW_DIALOG" value="false" />
@ -59,13 +66,18 @@
<property name="last_opened_file_path" value="$PROJECT_DIR$/src/etc/q1" /> <property name="last_opened_file_path" value="$PROJECT_DIR$/src/etc/q1" />
<property name="nodejs_interpreter_path.stuck_in_default_project" value="undefined stuck path" /> <property name="nodejs_interpreter_path.stuck_in_default_project" value="undefined stuck path" />
<property name="nodejs_npm_path_reset_for_default_project" value="true" /> <property name="nodejs_npm_path_reset_for_default_project" value="true" />
<property name="project.structure.last.edited" value="Modules" />
<property name="project.structure.proportion" value="0.0" />
<property name="project.structure.side.proportion" value="0.0" />
<property name="settings.editor.selected.configurable" value="preferences.pluginManager" /> <property name="settings.editor.selected.configurable" value="preferences.pluginManager" />
</component> </component>
<component name="RecentsManager"> <component name="RecentsManager">
<key name="CopyClassDialog.RECENTS_KEY"> <key name="CopyClassDialog.RECENTS_KEY">
<recent name="q101.f3" />
<recent name="q101.f2" />
<recent name="q23" />
<recent name="q21.f2" /> <recent name="q21.f2" />
<recent name="q6.f2" /> <recent name="q6.f2" />
<recent name="etc.ali.q2" />
</key> </key>
<key name="CopyFile.RECENT_KEYS"> <key name="CopyFile.RECENT_KEYS">
<recent name="$PROJECT_DIR$/src/etc/q1" /> <recent name="$PROJECT_DIR$/src/etc/q1" />
@ -73,13 +85,13 @@
<recent name="$PROJECT_DIR$/src/q206/f1" /> <recent name="$PROJECT_DIR$/src/q206/f1" />
</key> </key>
</component> </component>
<component name="RunManager" selected="Application.Solution"> <component name="RunManager" selected="Application.Solution (2)">
<configuration name="Solution (1)" type="Application" factoryName="Application" temporary="true" nameIsGenerated="true"> <configuration name="Solution (2)" type="Application" factoryName="Application" temporary="true" nameIsGenerated="true">
<option name="MAIN_CLASS_NAME" value="q46.f2.Solution" /> <option name="MAIN_CLASS_NAME" value="q101.f2.Solution" />
<module name="LeetCode" /> <module name="LeetCode" />
<extension name="coverage"> <extension name="coverage">
<pattern> <pattern>
<option name="PATTERN" value="q46.f2.*" /> <option name="PATTERN" value="q101.f2.*" />
<option name="ENABLED" value="true" /> <option name="ENABLED" value="true" />
</pattern> </pattern>
</extension> </extension>
@ -87,12 +99,12 @@
<option name="Make" enabled="true" /> <option name="Make" enabled="true" />
</method> </method>
</configuration> </configuration>
<configuration name="Solution (2)" type="Application" factoryName="Application" temporary="true" nameIsGenerated="true"> <configuration name="Solution (4)" type="Application" factoryName="Application" temporary="true" nameIsGenerated="true">
<option name="MAIN_CLASS_NAME" value="q746.Solution" /> <option name="MAIN_CLASS_NAME" value="q26.Solution" />
<module name="LeetCode" /> <module name="LeetCode" />
<extension name="coverage"> <extension name="coverage">
<pattern> <pattern>
<option name="PATTERN" value="q746.*" /> <option name="PATTERN" value="q26.*" />
<option name="ENABLED" value="true" /> <option name="ENABLED" value="true" />
</pattern> </pattern>
</extension> </extension>
@ -100,12 +112,12 @@
<option name="Make" enabled="true" /> <option name="Make" enabled="true" />
</method> </method>
</configuration> </configuration>
<configuration name="Solution (4)" type="Application" factoryName="Application" temporary="true" nameIsGenerated="true"> <configuration name="Solution (5)" type="Application" factoryName="Application" temporary="true" nameIsGenerated="true">
<option name="MAIN_CLASS_NAME" value="q26.Solution" /> <option name="MAIN_CLASS_NAME" value="q53.q2.Solution" />
<module name="LeetCode" /> <module name="LeetCode" />
<extension name="coverage"> <extension name="coverage">
<pattern> <pattern>
<option name="PATTERN" value="q26.*" /> <option name="PATTERN" value="q53.q2.*" />
<option name="ENABLED" value="true" /> <option name="ENABLED" value="true" />
</pattern> </pattern>
</extension> </extension>
@ -113,12 +125,12 @@
<option name="Make" enabled="true" /> <option name="Make" enabled="true" />
</method> </method>
</configuration> </configuration>
<configuration name="Solution (5)" type="Application" factoryName="Application" temporary="true" nameIsGenerated="true"> <configuration name="Solution" type="Application" factoryName="Application" temporary="true" nameIsGenerated="true">
<option name="MAIN_CLASS_NAME" value="q53.q2.Solution" /> <option name="MAIN_CLASS_NAME" value="q54.Solution" />
<module name="LeetCode" /> <module name="LeetCode" />
<extension name="coverage"> <extension name="coverage">
<pattern> <pattern>
<option name="PATTERN" value="q53.q2.*" /> <option name="PATTERN" value="q54.*" />
<option name="ENABLED" value="true" /> <option name="ENABLED" value="true" />
</pattern> </pattern>
</extension> </extension>
@ -127,11 +139,11 @@
</method> </method>
</configuration> </configuration>
<configuration name="Solution" type="Application" factoryName="Application" temporary="true" nameIsGenerated="true"> <configuration name="Solution" type="Application" factoryName="Application" temporary="true" nameIsGenerated="true">
<option name="MAIN_CLASS_NAME" value="q54.Solution" /> <option name="MAIN_CLASS_NAME" value="q101.f1.Solution" />
<module name="LeetCode" /> <module name="LeetCode" />
<extension name="coverage"> <extension name="coverage">
<pattern> <pattern>
<option name="PATTERN" value="q54.*" /> <option name="PATTERN" value="q101.f1.*" />
<option name="ENABLED" value="true" /> <option name="ENABLED" value="true" />
</pattern> </pattern>
</extension> </extension>
@ -167,11 +179,11 @@
</configuration> </configuration>
<recent_temporary> <recent_temporary>
<list> <list>
<item itemvalue="Application.Solution (2)" />
<item itemvalue="Application.Solution (3)" />
<item itemvalue="Application.Solution" /> <item itemvalue="Application.Solution" />
<item itemvalue="Application.Solution (5)" /> <item itemvalue="Application.Solution (5)" />
<item itemvalue="Application.Solution (5)" /> <item itemvalue="Application.Solution (5)" />
<item itemvalue="Application.Solution (1)" />
<item itemvalue="Application.Solution (2)" />
</list> </list>
</recent_temporary> </recent_temporary>
</component> </component>
@ -211,7 +223,7 @@
<workItem from="1579759214129" duration="10251000" /> <workItem from="1579759214129" duration="10251000" />
<workItem from="1580044287086" duration="50376000" /> <workItem from="1580044287086" duration="50376000" />
<workItem from="1580562331089" duration="8289000" /> <workItem from="1580562331089" duration="8289000" />
<workItem from="1580626297484" duration="13148000" /> <workItem from="1580626297484" duration="25851000" />
</task> </task>
<task id="LOCAL-00001" summary="add q5/q7/q172"> <task id="LOCAL-00001" summary="add q5/q7/q172">
<created>1580045439607</created> <created>1580045439607</created>
@ -276,7 +288,14 @@
<option name="project" value="LOCAL" /> <option name="project" value="LOCAL" />
<updated>1580714190854</updated> <updated>1580714190854</updated>
</task> </task>
<option name="localTasksCounter" value="10" /> <task id="LOCAL-00010" summary="add q54">
<created>1580753759299</created>
<option name="number" value="00010" />
<option name="presentableId" value="LOCAL-00010" />
<option name="project" value="LOCAL" />
<updated>1580753759299</updated>
</task>
<option name="localTasksCounter" value="11" />
<servers /> <servers />
</component> </component>
<component name="TypeScriptGeneratedFilesManager"> <component name="TypeScriptGeneratedFilesManager">
@ -292,73 +311,78 @@
<MESSAGE value="add q26/q43" /> <MESSAGE value="add q26/q43" />
<MESSAGE value="add q46" /> <MESSAGE value="add q46" />
<MESSAGE value="add q53" /> <MESSAGE value="add q53" />
<option name="LAST_COMMIT_MESSAGE" value="add q53" /> <MESSAGE value="add q54" />
<option name="LAST_COMMIT_MESSAGE" value="add q54" />
</component> </component>
<component name="WindowStateProjectService"> <component name="WindowStateProjectService">
<state x="320" y="115" key="#Project_Structure" timestamp="1580830129378">
<screen x="0" y="0" width="1440" height="900" />
</state>
<state x="320" y="115" key="#Project_Structure/0.0.1440.900@0.0.1440.900" timestamp="1580830129378" />
<state x="533" y="166" key="#com.intellij.ide.util.MemberChooser" timestamp="1578548165321"> <state x="533" y="166" key="#com.intellij.ide.util.MemberChooser" timestamp="1578548165321">
<screen x="0" y="0" width="1440" height="900" /> <screen x="0" y="0" width="1440" height="900" />
</state> </state>
<state x="533" y="166" key="#com.intellij.ide.util.MemberChooser/0.0.1440.900@0.0.1440.900" timestamp="1578548165321" /> <state x="533" y="166" key="#com.intellij.ide.util.MemberChooser/0.0.1440.900@0.0.1440.900" timestamp="1578548165321" />
<state x="303" y="50" key="CommitChangelistDialog2" timestamp="1580714190621"> <state x="303" y="50" key="CommitChangelistDialog2" timestamp="1580753759090">
<screen x="0" y="0" width="1440" height="900" /> <screen x="0" y="0" width="1440" height="900" />
</state> </state>
<state x="303" y="50" key="CommitChangelistDialog2/0.0.1440.900@0.0.1440.900" timestamp="1580714190621" /> <state x="303" y="50" key="CommitChangelistDialog2/0.0.1440.900@0.0.1440.900" timestamp="1580753759090" />
<state x="144" y="78" key="DiffContextDialog" timestamp="1580585072145"> <state x="144" y="78" key="DiffContextDialog" timestamp="1580585072145">
<screen x="0" y="0" width="1440" height="900" /> <screen x="0" y="0" width="1440" height="900" />
</state> </state>
<state x="144" y="78" key="DiffContextDialog/0.0.1440.900@0.0.1440.900" timestamp="1580585072145" /> <state x="144" y="78" key="DiffContextDialog/0.0.1440.900@0.0.1440.900" timestamp="1580585072145" />
<state width="1398" height="204" key="GridCell.Tab.0.bottom" timestamp="1580753043493"> <state width="1398" height="170" key="GridCell.Tab.0.bottom" timestamp="1580965027880">
<screen x="0" y="0" width="1440" height="900" /> <screen x="0" y="0" width="1440" height="900" />
</state> </state>
<state width="1398" height="204" key="GridCell.Tab.0.bottom/0.0.1440.900@0.0.1440.900" timestamp="1580753043493" /> <state width="1398" height="170" key="GridCell.Tab.0.bottom/0.0.1440.900@0.0.1440.900" timestamp="1580965027880" />
<state width="1398" height="204" key="GridCell.Tab.0.bottom/0.23.1440.797@0.23.1440.797" timestamp="1580706887662" /> <state width="1398" height="204" key="GridCell.Tab.0.bottom/0.23.1440.797@0.23.1440.797" timestamp="1580706887662" />
<state width="1398" height="204" key="GridCell.Tab.0.center" timestamp="1580753043491"> <state width="1398" height="170" key="GridCell.Tab.0.center" timestamp="1580965027878">
<screen x="0" y="0" width="1440" height="900" /> <screen x="0" y="0" width="1440" height="900" />
</state> </state>
<state width="1398" height="204" key="GridCell.Tab.0.center/0.0.1440.900@0.0.1440.900" timestamp="1580753043491" /> <state width="1398" height="170" key="GridCell.Tab.0.center/0.0.1440.900@0.0.1440.900" timestamp="1580965027878" />
<state width="1398" height="204" key="GridCell.Tab.0.center/0.23.1440.797@0.23.1440.797" timestamp="1580706887660" /> <state width="1398" height="204" key="GridCell.Tab.0.center/0.23.1440.797@0.23.1440.797" timestamp="1580706887660" />
<state width="1398" height="204" key="GridCell.Tab.0.left" timestamp="1580753043490"> <state width="1398" height="170" key="GridCell.Tab.0.left" timestamp="1580965027877">
<screen x="0" y="0" width="1440" height="900" /> <screen x="0" y="0" width="1440" height="900" />
</state> </state>
<state width="1398" height="204" key="GridCell.Tab.0.left/0.0.1440.900@0.0.1440.900" timestamp="1580753043490" /> <state width="1398" height="170" key="GridCell.Tab.0.left/0.0.1440.900@0.0.1440.900" timestamp="1580965027877" />
<state width="1398" height="204" key="GridCell.Tab.0.left/0.23.1440.797@0.23.1440.797" timestamp="1580706887659" /> <state width="1398" height="204" key="GridCell.Tab.0.left/0.23.1440.797@0.23.1440.797" timestamp="1580706887659" />
<state width="1398" height="204" key="GridCell.Tab.0.right" timestamp="1580753043492"> <state width="1398" height="170" key="GridCell.Tab.0.right" timestamp="1580965027879">
<screen x="0" y="0" width="1440" height="900" /> <screen x="0" y="0" width="1440" height="900" />
</state> </state>
<state width="1398" height="204" key="GridCell.Tab.0.right/0.0.1440.900@0.0.1440.900" timestamp="1580753043492" /> <state width="1398" height="170" key="GridCell.Tab.0.right/0.0.1440.900@0.0.1440.900" timestamp="1580965027879" />
<state width="1398" height="204" key="GridCell.Tab.0.right/0.23.1440.797@0.23.1440.797" timestamp="1580706887661" /> <state width="1398" height="204" key="GridCell.Tab.0.right/0.23.1440.797@0.23.1440.797" timestamp="1580706887661" />
<state width="1398" height="261" key="GridCell.Tab.1.bottom" timestamp="1580626092580"> <state width="1398" height="261" key="GridCell.Tab.1.bottom" timestamp="1580879325596">
<screen x="0" y="0" width="1440" height="900" /> <screen x="0" y="0" width="1440" height="900" />
</state> </state>
<state width="1398" height="261" key="GridCell.Tab.1.bottom/0.0.1440.900@0.0.1440.900" timestamp="1580626092580" /> <state width="1398" height="261" key="GridCell.Tab.1.bottom/0.0.1440.900@0.0.1440.900" timestamp="1580879325596" />
<state width="1398" height="304" key="GridCell.Tab.1.bottom/0.23.1440.797@0.23.1440.797" timestamp="1580408030266" /> <state width="1398" height="304" key="GridCell.Tab.1.bottom/0.23.1440.797@0.23.1440.797" timestamp="1580408030266" />
<state width="1398" height="261" key="GridCell.Tab.1.center" timestamp="1580626092579"> <state width="1398" height="261" key="GridCell.Tab.1.center" timestamp="1580879325595">
<screen x="0" y="0" width="1440" height="900" /> <screen x="0" y="0" width="1440" height="900" />
</state> </state>
<state width="1398" height="261" key="GridCell.Tab.1.center/0.0.1440.900@0.0.1440.900" timestamp="1580626092579" /> <state width="1398" height="261" key="GridCell.Tab.1.center/0.0.1440.900@0.0.1440.900" timestamp="1580879325595" />
<state width="1398" height="304" key="GridCell.Tab.1.center/0.23.1440.797@0.23.1440.797" timestamp="1580408030265" /> <state width="1398" height="304" key="GridCell.Tab.1.center/0.23.1440.797@0.23.1440.797" timestamp="1580408030265" />
<state width="1398" height="261" key="GridCell.Tab.1.left" timestamp="1580626092578"> <state width="1398" height="261" key="GridCell.Tab.1.left" timestamp="1580879325593">
<screen x="0" y="0" width="1440" height="900" /> <screen x="0" y="0" width="1440" height="900" />
</state> </state>
<state width="1398" height="261" key="GridCell.Tab.1.left/0.0.1440.900@0.0.1440.900" timestamp="1580626092578" /> <state width="1398" height="261" key="GridCell.Tab.1.left/0.0.1440.900@0.0.1440.900" timestamp="1580879325593" />
<state width="1398" height="304" key="GridCell.Tab.1.left/0.23.1440.797@0.23.1440.797" timestamp="1580408030262" /> <state width="1398" height="304" key="GridCell.Tab.1.left/0.23.1440.797@0.23.1440.797" timestamp="1580408030262" />
<state width="1398" height="261" key="GridCell.Tab.1.right" timestamp="1580626092579"> <state width="1398" height="261" key="GridCell.Tab.1.right" timestamp="1580879325595">
<screen x="0" y="0" width="1440" height="900" /> <screen x="0" y="0" width="1440" height="900" />
</state> </state>
<state width="1398" height="261" key="GridCell.Tab.1.right/0.0.1440.900@0.0.1440.900" timestamp="1580626092579" /> <state width="1398" height="261" key="GridCell.Tab.1.right/0.0.1440.900@0.0.1440.900" timestamp="1580879325595" />
<state width="1398" height="304" key="GridCell.Tab.1.right/0.23.1440.797@0.23.1440.797" timestamp="1580408030266" /> <state width="1398" height="304" key="GridCell.Tab.1.right/0.23.1440.797@0.23.1440.797" timestamp="1580408030266" />
<state x="221" y="88" key="SettingsEditor" timestamp="1580562273160"> <state x="221" y="88" key="SettingsEditor" timestamp="1580562273160">
<screen x="0" y="0" width="1440" height="900" /> <screen x="0" y="0" width="1440" height="900" />
</state> </state>
<state x="221" y="88" key="SettingsEditor/0.0.1440.900@0.0.1440.900" timestamp="1580562273160" /> <state x="221" y="88" key="SettingsEditor/0.0.1440.900@0.0.1440.900" timestamp="1580562273160" />
<state x="320" y="190" key="Vcs.Push.Dialog.v2" timestamp="1580714192376"> <state x="320" y="190" key="Vcs.Push.Dialog.v2" timestamp="1580753760718">
<screen x="0" y="0" width="1440" height="900" /> <screen x="0" y="0" width="1440" height="900" />
</state> </state>
<state x="320" y="190" key="Vcs.Push.Dialog.v2/0.0.1440.900@0.0.1440.900" timestamp="1580714192376" /> <state x="320" y="190" key="Vcs.Push.Dialog.v2/0.0.1440.900@0.0.1440.900" timestamp="1580753760718" />
<state x="378" y="207" width="683" height="486" key="find.popup" timestamp="1578496174047"> <state x="378" y="207" width="683" height="486" key="find.popup" timestamp="1580830143783">
<screen x="0" y="0" width="1440" height="900" /> <screen x="0" y="0" width="1440" height="900" />
</state> </state>
<state x="378" y="207" width="683" height="486" key="find.popup/0.0.1440.900@0.0.1440.900" timestamp="1578496174047" /> <state x="378" y="207" width="683" height="486" key="find.popup/0.0.1440.900@0.0.1440.900" timestamp="1580830143783" />
<state x="385" y="196" width="670" height="676" key="search.everywhere.popup" timestamp="1580563351587"> <state x="385" y="196" width="670" height="676" key="search.everywhere.popup" timestamp="1580563351587">
<screen x="0" y="0" width="1440" height="900" /> <screen x="0" y="0" width="1440" height="900" />
</state> </state>

66
src/q101/f1/Solution.java
Unescape View File

@ -0,0 +1,66 @@
package q101.f1;
import java.util.ArrayList;
import java.util.List;
/**
* 层序遍历放入list对比 o(n*log(n))
*/
public class Solution {
public boolean isSymmetric(List<TreeNode> nodes) {
if (nodes.size() < 2) {
return true;
}
int i = 0;
int j = nodes.size() - 1;
while (i < j) {
if (nodes.get(i) == nodes.get(j)) {
i++;
j--;
} else if (nodes.get(i) == null || nodes.get(j) == null || nodes.get(i).val != nodes.get(j).val) {
return false;
} else {
i++;
j--;
}
}
return true;
}
public boolean isSymmetric(TreeNode root) {
List<TreeNode> list = new ArrayList<>();
list.add(root);
while (list.size() != 0) {
List<TreeNode> temp = new ArrayList<>();
for (int i = 0; i < list.size(); i++) {
if (list.get(i) != null) {
temp.add(list.get(i).left);
temp.add(list.get(i).right);
}
}
if (!isSymmetric(temp)) {
return false;
}
list = temp;
}
return true;
}
public static void main(String[] args) {
TreeNode root = new TreeNode(1);
TreeNode t1 = new TreeNode(2);
TreeNode t2 = new TreeNode(2);
root.left = t1;
root.right = t2;
TreeNode t3 = new TreeNode(3);
TreeNode t4 = new TreeNode(4);
t1.left = t3;
t1.right = t4;
TreeNode t5 = new TreeNode(4);
TreeNode t6 = new TreeNode(3);
t2.left = t5;
t2.right = t6;
System.out.println(new Solution().isSymmetric(root));
}
}

11
src/q101/f1/TreeNode.java
Unescape View File

@ -0,0 +1,11 @@
package q101.f1;
public class TreeNode {
int val;
TreeNode left;
TreeNode right;
TreeNode(int x) {
val = x;
}
}

51
src/q101/f2/Solution.java
Unescape View File

@ -0,0 +1,51 @@
package q101.f2;
import java.util.LinkedList;
import java.util.Queue;
/**
* 利用队列的层序遍历（广度优先搜索BFS）o(n)
*/
public class Solution {
public boolean isSymmetric(TreeNode root) {
Queue<TreeNode> q = new LinkedList<>();
q.add(root);
q.add(root);
while (!q.isEmpty()) {
TreeNode t1 = q.poll();
TreeNode t2 = q.poll();
if (t1 == null && t2 == null) {
continue;
}
if (t1 == null || t2 == null) {
return false;
}
if (t1.val != t2.val) {
return false;
}
q.add(t1.left);
q.add(t2.right);
q.add(t1.right);
q.add(t2.left);
}
return true;
}
public static void main(String[] args) {
TreeNode root = new TreeNode(1);
TreeNode t1 = new TreeNode(2);
TreeNode t2 = new TreeNode(2);
root.left = t1;
root.right = t2;
TreeNode t3 = new TreeNode(3);
TreeNode t4 = new TreeNode(4);
t1.left = t3;
t1.right = t4;
TreeNode t5 = new TreeNode(4);
TreeNode t6 = new TreeNode(3);
t2.left = t5;
t2.right = t6;
System.out.println(new Solution().isSymmetric(root));
}
}

11
src/q101/f2/TreeNode.java
Unescape View File

@ -0,0 +1,11 @@
package q101.f2;
public class TreeNode {
int val;
TreeNode left;
TreeNode right;
TreeNode(int x) {
val = x;
}
}

22
src/q101/f3/Solution.java
Unescape View File

@ -0,0 +1,22 @@
package q101.f3;
/**
* 递归 o(n)（如果一个树的左子树与右子树镜像对称，那么这个树是对称的。根结点相同并且每个树的左子树和另一个树的右子树镜像对称的树是镜像对称的）
*/
public class Solution {
public boolean isSymmetric(TreeNode root) {
return isMirror(root, root);
}
public boolean isMirror(TreeNode t1, TreeNode t2) {
if (t1 == null && t2 == null) {
return true;
}
if (t1 == null || t2 == null) {
return false;
}
return (t1.val == t2.val)
&& isMirror(t1.right, t2.left)
&& isMirror(t1.left, t2.right);
}
}

11
src/q101/f3/TreeNode.java
Unescape View File

@ -0,0 +1,11 @@
package q101.f3;
public class TreeNode {
int val;
TreeNode left;
TreeNode right;
TreeNode(int x) {
val = x;
}
}

10
src/q23/ListNode.java
Unescape View File

@ -0,0 +1,10 @@
package q23;
public class ListNode {
int val;
ListNode next;
ListNode(int x) {
val = x;
}
}

49
src/q23/Solution.java
Unescape View File

@ -0,0 +1,49 @@
package q23;
/**
* 做k-1次mergeTwoLists o(N*k) 可用分治法优化至o(N*log(k))) N为所有list的总节点数
*/
class Solution {
public ListNode mergeTwoLists(ListNode l1, ListNode l2) {
if (l1 == null) {
return l2;
}
if (l2 == null) {
return l1;
}
ListNode head = new ListNode(Integer.MIN_VALUE);
head.next = l1;
ListNode pre = head;
while (l2 != null) {
ListNode t1 = pre.next;
ListNode t2 = l2.next;
while (l2.val > t1.val) {
if (t1.next == null) {
t1.next = l2;
return head.next;
} else {
pre = pre.next;
t1 = t1.next;
}
}
pre.next = l2;
l2.next = t1;
l2 = t2;
}
return head.next;
}
public ListNode mergeKLists(ListNode[] lists) {
if (lists.length == 0) {
return null;
}
if (lists.length == 1) {
return lists[0];
}
ListNode result = lists[0];
for (int i = 1; i < lists.length; i++) {
result = mergeTwoLists(result, lists[i]);
}
return result;
}
}
Write Preview
Loading…
Cancel
Save