1.bit

.idea/.gitignore

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+# Default ignored files
+/workspace.xml

.idea/misc.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectRootManager" version="2" project-jdk-name="1.8" project-jdk-type="JavaSDK">
+    <output url="file://$PROJECT_DIR$/out" />
+  </component>
+</project>

.idea/modules.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectModuleManager">
+    <modules>
+      <module fileurl="file://$PROJECT_DIR$/wc_algorithm.iml" filepath="$PROJECT_DIR$/wc_algorithm.iml" />
+    </modules>
+  </component>
+</project>

.idea/vcs.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="" vcs="Git" />
+  </component>
+</project>

src/com/bradley/bit/Bit.java

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+package com.bradley.bit;
+
+public class Bit {
+
+    public static void printBit(){
+        int n = 1;
+        System.out.println(1<<32);
+        System.out.println(1<<31);
+        System.out.println(1<<30);
+        System.out.println(1<<29);
+        // 1 用二进制表示 32bit ==>  00000000 00000000 00000000 00000001  1*2^0 = 1
+        // 1 左移32位          ==> 10000000 00000000 00000000 000000000  0*2^0 = 0
+        // 1 左移31位          ==>  01000000 00000000 00000000 00000000  1*2^31 = 2147483648 4294967296  超出int范围：2147483647  变成了 -2147483648
+        // 1 左移30位          ==>  00100000 00000000 00000000 00000000  1*2^30 = 1
+        // 1 左移29位          ==>  00010000 00000000 00000000 00000000  1*2^29 = 1
+
+    }
+
+    public static void main(String[] args) {
+//        System.out.println(Integer.MAX_VALUE);
+        printBit();
+    }
+}

wc_algorithm.iml

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+<?xml version="1.0" encoding="UTF-8"?>
+<module type="WEB_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>