diff --git a/算法分析思路/分治算法.md b/算法分析思路/分治算法.md
new file mode 100644
index 0000000..e69de29
diff --git a/算法分析思路/动态规划.md b/算法分析思路/动态规划.md
new file mode 100644
index 0000000..e69de29
diff --git a/算法分析思路/回溯法.md b/算法分析思路/回溯法.md
new file mode 100644
index 0000000..e69de29
diff --git a/算法分析思路/枚举迭代.md b/算法分析思路/枚举迭代.md
new file mode 100644
index 0000000..e69de29
diff --git a/算法分析思路/贪心算法.md b/算法分析思路/贪心算法.md
new file mode 100644
index 0000000..e69de29
diff --git a/算法分析思路/递归.md b/算法分析思路/递归.md
new file mode 100644
index 0000000..e69de29
diff --git a/算法问题选编/测试代码/1.c b/算法问题选编/测试代码/1.c
new file mode 100644
index 0000000..67829ea
--- /dev/null
+++ b/算法问题选编/测试代码/1.c
@@ -0,0 +1,37 @@
+
+#include "stdio.h"
+#include "string.h"
+
+int string_to_integer(char *s,int length){
+
+	if (length>1)
+	{
+		return s[0]=='-'?string_to_integer(s,length-1)*10-(s[length-1]-'0'):string_to_integer(s,length-1)*10+s[length-1]-'0';
+	}else{
+		return s[0]=='-'?-1/10:s[0]-'0';
+
+	}
+}
+	
+/* 问题：
+1. s是空字符串
+2. s传参为非数字字符
+3. 超出整数所能表示范围
+*/
+
+
+int main(){
+
+	char *s = "4323";
+
+	printf("integer == %d\n",string_to_integer(s,strlen(s)) );
+	printf("integer == %d\n",string_to_integer("12342",5));
+	printf("integer == %d\n",string_to_integer("-11",3) );
+	printf("integer == %d\n",string_to_integer("-5",2) );
+	printf("integer == %d\n", string_to_integer("3",1));
+
+	printf("integer == %d\n", string_to_integer("abcd",4));
+	printf("integer == %d\n", string_to_integer("a",1));
+
+	return 0;
+}
diff --git a/算法问题选编/测试代码/2.c b/算法问题选编/测试代码/2.c
new file mode 100644
index 0000000..b8f86c9
--- /dev/null
+++ b/算法问题选编/测试代码/2.c
@@ -0,0 +1,23 @@
+
+#include "stdio.h"
+
+
+int factorial(int n){
+
+	int ret=0;
+	(n==0) || (ret=n+factorial(n-1));
+	return ret;
+}
+
+
+int main(){
+
+	int n=10;
+	printf("factorial(10)= %d\n",factorial(10));
+	printf("factorial(5)= %d\n",factorial(5));
+	printf("factorial(1)= %d\n",factorial(1));
+	printf("factorial(0)= %d\n",factorial(0));
+
+	return 0;
+}
+
diff --git a/算法问题选编/测试代码/3.c b/算法问题选编/测试代码/3.c
new file mode 100644
index 0000000..669624e
--- /dev/null
+++ b/算法问题选编/测试代码/3.c
@@ -0,0 +1,71 @@
+
+#include "stdio.h"
+#include "stdlib.h"
+
+char *integer_to_bin(long integer){
+
+	int bit_num = sizeof(long)*8;
+	char *buffer= (char *)malloc(bit_num+1);
+	if (buffer==NULL)
+	{
+		return "malloc error";
+	}
+	buffer[bit_num]='\0';
+
+	for (int i = 0; i < bit_num; ++i)
+	{
+		buffer[i]= integer<<i>>(bit_num-1);
+		buffer[i]= buffer[i]==0?'0':'1';
+
+	}
+	return buffer;
+
+}
+
+char *integer_to_hex(long integer){
+
+	int bit_num=sizeof(long)*8/4;
+	char *buffer=(char *)malloc(bit_num+3);
+	buffer[0]='0';
+	buffer[1]='x';
+	buffer[bit_num+2]='\0';
+	char *tmp=&buffer[2];
+
+	for (int i = 0; i < bit_num; i++)
+	{
+		tmp[i]= integer<<(i*4)>>(bit_num*4-4);
+		tmp[i]= tmp[i]>=0?tmp[i]:tmp[i]+16;
+		tmp[i]= tmp[i]<10?(tmp[i]+48):(tmp[i]-10+'A');
+	}
+
+	return buffer;
+}
+
+
+/*
+
+A  65
+0  48
+
+*/
+
+
+
+int main(){
+
+
+	printf("b(11) = %s\n", integer_to_bin(11));
+	printf("b(1023) = %s\n",integer_to_bin(1023) );
+	printf("b(23564) = %s\n",integer_to_bin(23564) );
+
+
+	printf("h(11) = %s\n", integer_to_hex(11));
+	printf("h(1023) = %s\n",integer_to_hex(1023) );
+	printf("h(23564) = %s\n",integer_to_hex(23564) );
+	printf("b(11) = %x\n", 11);
+	printf("b(1023) = %x\n",1023 );
+	printf("b(23564) = %x\n",23564 );
+
+
+	return 0;
+}
\ No newline at end of file
diff --git a/算法问题选编/测试代码/4-1.c b/算法问题选编/测试代码/4-1.c
new file mode 100644
index 0000000..806e7d3
--- /dev/null
+++ b/算法问题选编/测试代码/4-1.c
@@ -0,0 +1,7 @@
+#include "stdio.h"
+
+int main(){
+
+	printf("%ld",236432123443*33453098);
+	return 0;
+}
\ No newline at end of file
diff --git a/算法问题选编/测试代码/5.c b/算法问题选编/测试代码/5.c
new file mode 100644
index 0000000..4df163b
--- /dev/null
+++ b/算法问题选编/测试代码/5.c
@@ -0,0 +1,25 @@
+
+
+#include "stdio.h"
+
+
+/*
+
+	1 是第一个元素
+	序列中元素被2或3或5整除
+
+*/
+unsigned long value_in_sequence(unsigned index){
+
+	
+
+
+}
+
+
+int main(){
+
+
+
+	return 0;
+}
\ No newline at end of file
diff --git a/算法问题选编/测试代码/6.c b/算法问题选编/测试代码/6.c
new file mode 100644
index 0000000..926f346
--- /dev/null
+++ b/算法问题选编/测试代码/6.c
@@ -0,0 +1,70 @@
+
+
+#include "stdio.h"
+
+int binary_search_first(int *a,int length,int key){
+
+	int low=0;
+	int high = length-1;
+	int mid = 0;
+
+	while(low<high){
+
+		mid = (low+high)/2;
+		if (a[mid]>=key)//往左找
+		{
+			high = mid;
+		}else{
+
+			low = mid+1;
+		}
+
+	}
+	return high;
+
+}
+
+int binary_search_last(int *a,int length,int key){
+
+	int low = 0;
+	int high = length -1;
+	int mid = 0;
+
+	while(low<high){
+
+		mid = (low+high+1)/2;
+		if (a[mid]<=key)// 往右找	
+		{
+			low=mid;
+		}else{
+			high = mid-1;
+		}
+
+	}
+
+	return low;
+}
+
+
+int element_appear_times(int *a,int length,int key){
+
+	printf("(%d) first appear at index %d\n",key,binary_search_first(a,length,key));
+	printf("(%d) last appear at index %d\n",key,binary_search_last(a,length,key));
+	return binary_search_last(a,length,key)-binary_search_first(a,length,key)+1;
+
+}
+
+
+int main(){
+
+
+	int a[] = {2,3,4,4,4,4,4,5,5,7,7,11,11,11,11,11,32,32,54};
+
+	printf("(2)appear times = %d\n", element_appear_times(a,sizeof(a)/sizeof(int),2) );
+	printf("(4)appear times = %d\n", element_appear_times(a,sizeof(a)/sizeof(int),4) );
+	printf("(11)appear times = %d\n", element_appear_times(a,sizeof(a)/sizeof(int),11) );
+	printf("(36)appear times = %d\n", element_appear_times(a,sizeof(a)/sizeof(int),36) );
+	printf("(54)appear times = %d\n", element_appear_times(a,sizeof(a)/sizeof(int),54) );
+	return 0;
+}
+
diff --git a/算法问题选编/测试代码/7.c b/算法问题选编/测试代码/7.c
new file mode 100644
index 0000000..178b4ab
--- /dev/null
+++ b/算法问题选编/测试代码/7.c
@@ -0,0 +1,14 @@
+
+#include "stdio.h"
+
+int main(){
+
+	int j,k,m;
+	int i= (j=4,k=5,m=8);
+	printf("%d\n", i);
+
+	i= (j==4)?:0;
+	printf("i=%d\n", i);
+
+	return 0;
+}
diff --git a/算法问题选编/测试代码/a.out b/算法问题选编/测试代码/a.out
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index 0000000..75733a7
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diff --git a/算法问题选编/测试代码/a.out.dSYM/Contents/Info.plist b/算法问题选编/测试代码/a.out.dSYM/Contents/Info.plist
new file mode 100644
index 0000000..3679a65
--- /dev/null
+++ b/算法问题选编/测试代码/a.out.dSYM/Contents/Info.plist
@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+	<dict>
+		<key>CFBundleDevelopmentRegion</key>
+		<string>English</string>
+		<key>CFBundleIdentifier</key>
+		<string>com.apple.xcode.dsym.a.out</string>
+		<key>CFBundleInfoDictionaryVersion</key>
+		<string>6.0</string>
+		<key>CFBundlePackageType</key>
+		<string>dSYM</string>
+		<key>CFBundleSignature</key>
+		<string>????</string>
+		<key>CFBundleShortVersionString</key>
+		<string>1.0</string>
+		<key>CFBundleVersion</key>
+		<string>1</string>
+	</dict>
+</plist>
diff --git a/算法问题选编/测试代码/a.out.dSYM/Contents/Resources/DWARF/a.out b/算法问题选编/测试代码/a.out.dSYM/Contents/Resources/DWARF/a.out
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