leetcode 1

Author: tangfire

.gitignore

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+### IntelliJ IDEA ###
+out/
+!**/src/main/**/out/
+!**/src/test/**/out/
+
+### Eclipse ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+bin/
+!**/src/main/**/bin/
+!**/src/test/**/bin/
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+
+### VS Code ###
+.vscode/
+
+### Mac OS ###
+.DS_Store

.idea/.gitignore

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+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>

.idea/misc.xml

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+//TIP 要<b>运行</b>代码，请按 <shortcut actionId="Run"/> 或
+// 点击装订区域中的 <icon src="AllIcons.Actions.Execute"/> 图标。
+public class Main {
+    public static void main(String[] args) {
+        //TIP 当文本光标位于高亮显示的文本处时按 <shortcut actionId="ShowIntentionActions"/>
+        // 查看 IntelliJ IDEA 建议如何修正。
+        System.out.printf("Hello and welcome!");
+
+        for (int i = 1; i <= 5; i++) {
+            //TIP 按 <shortcut actionId="Debug"/> 开始调试代码。我们已经设置了一个 <icon src="AllIcons.Debugger.Db_set_breakpoint"/> 断点
+            // 但您始终可以通过按 <shortcut actionId="ToggleLineBreakpoint"/> 添加更多断点。
+            System.out.println("i = " + i);
+        }
+    }
+}

.idea/modules.xml

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+package leetcode1;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class Main {
+    public static void main(String[] args){
+        int[] nums = new int[]{2,7,11,15};
+
+        int target = 9;
+
+        int[] map = twoSum(nums,target);
+        for (int i:map){
+            System.out.println(i);
+        }
+
+
+
+    }
+
+    public static int[] twoSum(int[] nums,int target){
+        Map<Integer,Integer> map = new HashMap<>();
+        for(int i=0;i<nums.length;i++){
+            if(map.containsKey(target-nums[i])){
+                return new int[]{map.get(target-nums[i]),i};
+            }else{
+                map.put(nums[i],i);
+            }
+        }
+        throw new IllegalArgumentException("No two sum solution");
+    }
+}