[Function add]

1. Add leetcode solutions.

Author: Seanforfun

Algorithm(4th_Edition)/.idea/misc.xml

@@ -0,0 +1,27 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="EclipseModuleManager">
+    <libelement value="jar://$MODULE_DIR$/lib/algs4.jar!/" />
+    <src_description expected_position="0">
+      <src_folder value="file://$MODULE_DIR$/src" expected_position="0" />
+    </src_description>
+  </component>
+  <component name="NewModuleRootManager">
+    <output url="file://$MODULE_DIR$/bin" />
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
+    </content>
+    <orderEntry type="sourceFolder" forTests="false" />
+    <orderEntry type="jdk" jdkName="jre" jdkType="JavaSDK" />
+    <orderEntry type="module-library">
+      <library name="algs4.jar">
+        <CLASSES>
+          <root url="jar://$MODULE_DIR$/lib/algs4.jar!/" />
+        </CLASSES>
+        <JAVADOC />
+        <SOURCES />
+      </library>
+    </orderEntry>
+  </component>
+</module>

Algorithm(4th_Edition)/.idea/modules.xml

@@ -381,6 +381,8 @@
 
 [217. Contains Duplicate](https://github.com/Seanforfun/Algorithm-and-Leetcode/blob/master/leetcode/217.%20Contains%20Duplicate.md)
 
+[219. Contains Duplicate II](https://github.com/Seanforfun/Algorithm-and-Leetcode/blob/master/leetcode/219.%20Contains%20Duplicate%20II.md)
+
 ## Algorithm(4th_Edition)
 Reading notes of book Algorithm(4th Algorithm),ISBN: 9787115293800.
 All java realization codes are placed in different packages.

Algorithm(4th_Edition)/.idea/vcs.xml

@@ -39,4 +39,21 @@ class Solution {
         return false;
     }
 }
+```
+
+### 二刷
+```Java
+class Solution {
+    public boolean containsNearbyDuplicate(int[] nums, int k) {
+        Map<Integer, Integer> map = new HashMap<>();
+        for(int i = 0; i < nums.length; i++){
+            int cur = nums[i];
+            if(map.containsKey(cur)){
+                if(i - map.get(cur) <= k) return true;
+            }
+            map.put(cur, i);
+        }
+        return false;
+    }
+}
 ```