diff --git a/15_NumberOf1InBinary/15_NumberOf1InBinary.vcxproj b/15_NumberOf1InBinary/15_NumberOf1InBinary.vcxproj
new file mode 100644
index 0000000..3a37322
--- /dev/null
+++ b/15_NumberOf1InBinary/15_NumberOf1InBinary.vcxproj
@@ -0,0 +1,150 @@
+
+
+
+
+ Debug
+ Win32
+
+
+ Release
+ Win32
+
+
+ Debug
+ x64
+
+
+ Release
+ x64
+
+
+
+ {A9AF95C4-4FA9-4A7E-B005-005777651659}
+ Win32Proj
+ My15_NumberOf1InBinary
+ 8.1
+
+
+
+ Application
+ true
+ v140
+ Unicode
+
+
+ Application
+ false
+ v140
+ true
+ Unicode
+
+
+ Application
+ true
+ v140
+ Unicode
+
+
+ Application
+ false
+ v140
+ true
+ Unicode
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ true
+
+
+ true
+
+
+ false
+
+
+ false
+
+
+
+
+
+ Level3
+ Disabled
+ WIN32;_DEBUG;_CONSOLE;%(PreprocessorDefinitions)
+
+
+ Console
+ true
+
+
+
+
+
+
+ Level3
+ Disabled
+ _DEBUG;_CONSOLE;%(PreprocessorDefinitions)
+
+
+ Console
+ true
+
+
+
+
+ Level3
+
+
+ MaxSpeed
+ true
+ true
+ WIN32;NDEBUG;_CONSOLE;%(PreprocessorDefinitions)
+
+
+ Console
+ true
+ true
+ true
+
+
+
+
+ Level3
+
+
+ MaxSpeed
+ true
+ true
+ NDEBUG;_CONSOLE;%(PreprocessorDefinitions)
+
+
+ Console
+ true
+ true
+ true
+
+
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\ No newline at end of file
diff --git a/15_NumberOf1InBinary/15_NumberOf1InBinary.vcxproj.filters b/15_NumberOf1InBinary/15_NumberOf1InBinary.vcxproj.filters
new file mode 100644
index 0000000..c3ba673
--- /dev/null
+++ b/15_NumberOf1InBinary/15_NumberOf1InBinary.vcxproj.filters
@@ -0,0 +1,22 @@
+
+
+
+
+ {4FC737F1-C7A5-4376-A066-2A32D752A2FF}
+ cpp;c;cc;cxx;def;odl;idl;hpj;bat;asm;asmx
+
+
+ {93995380-89BD-4b04-88EB-625FBE52EBFB}
+ h;hh;hpp;hxx;hm;inl;inc;xsd
+
+
+ {67DA6AB6-F800-4c08-8B7A-83BB121AAD01}
+ rc;ico;cur;bmp;dlg;rc2;rct;bin;rgs;gif;jpg;jpeg;jpe;resx;tiff;tif;png;wav;mfcribbon-ms
+
+
+
+
+ Source Files
+
+
+
\ No newline at end of file
diff --git a/15_NumberOf1InBinary/NumberOf1InBinary.cpp b/15_NumberOf1InBinary/NumberOf1InBinary.cpp
new file mode 100644
index 0000000..d37c122
--- /dev/null
+++ b/15_NumberOf1InBinary/NumberOf1InBinary.cpp
@@ -0,0 +1,80 @@
+//==================================================================
+// ¡¶½£Ö¸Offer¡ª¡ªÃûÆóÃæÊÔ¹Ù¾«½²µäÐͱà³ÌÌâ¡·´úÂë
+// Öø×÷ȨËùÓÐÕߣººÎº£ÌÎ
+//==================================================================
+
+// ÃæÊÔÌâ15£º¶þ½øÖÆÖÐ1µÄ¸öÊý
+// ÌâÄ¿£ºÇëʵÏÖÒ»¸öº¯Êý£¬ÊäÈëÒ»¸öÕûÊý£¬Êä³ö¸ÃÊý¶þ½øÖƱíʾÖÐ1µÄ¸öÊý¡£ÀýÈç
+// °Ñ9±íʾ³É¶þ½øÖÆÊÇ1001£¬ÓÐ2λÊÇ1¡£Òò´ËÈç¹ûÊäÈë9£¬¸Ãº¯ÊýÊä³ö2¡£
+
+#include "cstdio"
+
+int NumberOf1_Solution1(int n)
+{
+ int count = 0;
+ unsigned int flag = 1;
+ while (flag)
+ {
+ if (n & flag)
+ count++;
+
+ flag = flag << 1;
+ }
+
+ return count;
+}
+
+int NumberOf1_Solution2(int n)
+{
+ int count = 0;
+
+ while (n)
+ {
+ ++count;
+ n = (n - 1) & n;
+ }
+
+ return count;
+}
+
+// ====================²âÊÔ´úÂë====================
+void Test(int number, unsigned int expected)
+{
+ int actual = NumberOf1_Solution1(number);
+ if (actual == expected)
+ printf("Solution1: Test for %p passed.\n", number);
+ else
+ printf("Solution1: Test for %p failed.\n", number);
+
+ actual = NumberOf1_Solution2(number);
+ if (actual == expected)
+ printf("Solution2: Test for %p passed.\n", number);
+ else
+ printf("Solution2: Test for %p failed.\n", number);
+
+ printf("\n");
+}
+
+int main(int argc, char* argv[])
+{
+ // ÊäÈë0£¬ÆÚ´ýµÄÊä³öÊÇ0
+ Test(0, 0);
+
+ // ÊäÈë1£¬ÆÚ´ýµÄÊä³öÊÇ1
+ Test(1, 1);
+
+ // ÊäÈë10£¬ÆÚ´ýµÄÊä³öÊÇ2
+ Test(10, 2);
+
+ // ÊäÈë0x7FFFFFFF£¬ÆÚ´ýµÄÊä³öÊÇ31
+ Test(0x7FFFFFFF, 31);
+
+ // ÊäÈë0xFFFFFFFF£¨¸ºÊý£©£¬ÆÚ´ýµÄÊä³öÊÇ32
+ Test(0xFFFFFFFF, 32);
+
+ // ÊäÈë0x80000000£¨¸ºÊý£©£¬ÆÚ´ýµÄÊä³öÊÇ1
+ Test(0x80000000, 1);
+
+ return 0;
+}
+
diff --git a/CodingInterviewChinese2.sln b/CodingInterviewChinese2.sln
index bda7c5c..aad3b02 100644
--- a/CodingInterviewChinese2.sln
+++ b/CodingInterviewChinese2.sln
@@ -38,6 +38,8 @@ Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "13_RobotMove", "13_RobotMov
EndProject
Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "14_CuttingRope", "14_CuttingRope\14_CuttingRope.vcxproj", "{FF7ED3B0-5CE4-4D7B-954A-9EE93936D9A1}"
EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "15_NumberOf1InBinary", "15_NumberOf1InBinary\15_NumberOf1InBinary.vcxproj", "{A9AF95C4-4FA9-4A7E-B005-005777651659}"
+EndProject
Global
GlobalSection(SolutionConfigurationPlatforms) = preSolution
Debug|Any CPU = Debug|Any CPU
@@ -210,6 +212,16 @@ Global
{FF7ED3B0-5CE4-4D7B-954A-9EE93936D9A1}.Release|x64.Build.0 = Release|x64
{FF7ED3B0-5CE4-4D7B-954A-9EE93936D9A1}.Release|x86.ActiveCfg = Release|Win32
{FF7ED3B0-5CE4-4D7B-954A-9EE93936D9A1}.Release|x86.Build.0 = Release|Win32
+ {A9AF95C4-4FA9-4A7E-B005-005777651659}.Debug|Any CPU.ActiveCfg = Debug|Win32
+ {A9AF95C4-4FA9-4A7E-B005-005777651659}.Debug|x64.ActiveCfg = Debug|x64
+ {A9AF95C4-4FA9-4A7E-B005-005777651659}.Debug|x64.Build.0 = Debug|x64
+ {A9AF95C4-4FA9-4A7E-B005-005777651659}.Debug|x86.ActiveCfg = Debug|Win32
+ {A9AF95C4-4FA9-4A7E-B005-005777651659}.Debug|x86.Build.0 = Debug|Win32
+ {A9AF95C4-4FA9-4A7E-B005-005777651659}.Release|Any CPU.ActiveCfg = Release|Win32
+ {A9AF95C4-4FA9-4A7E-B005-005777651659}.Release|x64.ActiveCfg = Release|x64
+ {A9AF95C4-4FA9-4A7E-B005-005777651659}.Release|x64.Build.0 = Release|x64
+ {A9AF95C4-4FA9-4A7E-B005-005777651659}.Release|x86.ActiveCfg = Release|Win32
+ {A9AF95C4-4FA9-4A7E-B005-005777651659}.Release|x86.Build.0 = Release|Win32
EndGlobalSection
GlobalSection(SolutionProperties) = preSolution
HideSolutionNode = FALSE