diff --git a/1.cpp b/1.cpp
index 190c209..21dea71 100644
--- a/1.cpp
+++ b/1.cpp
@@ -2,27 +2,32 @@
 using namespace std;
 
 class container {
-
+protected:
 	int size;
 public:
 	float* p;
-	container(int s) :size(s){}
-	const int& getsize() { return size;}
-
+	container(int s) :size(s) {}
+	int& getsize() { return size; }
+	friend class vector;
 };
 
 class vector :public container {
 
 	int call_num;
 public:
-	explicit vector(int l) :len(l),size(1 * 100){
+	explicit vector(int l) :len(l), container(1 * 100) {
 		p = new float();
 	}
 	int len;
-	int& getlen() const {
-		call_num ++;
+	int& getlen(){
+		call_num++;
 		return len;
 	}
+	vector(const container& x):container(1*100) {
+		size = x.size;
+		p = new float[x.size];
+		len = 0;
+	}
 	~vector() = default;
 };
 
@@ -34,7 +39,7 @@ int main() {
 	container c2 = 100;
 	c2.getsize() = 20;
 	cout << c2.getsize();
-	vector v2 = 100;
-	v2.getlen = 40;
+	vector v2 (100);
+	v2.getlen() = 40;
 	cout << v2.getlen();
-}
\ No newline at end of file
+}
diff --git a/2.cpp b/2.cpp
index 6a27746..58e302a 100644
--- a/2.cpp
+++ b/2.cpp
@@ -5,11 +5,11 @@ using namespace std;
 
 // count all the specific char in the whole array of strings
 int countAllSpecificChars(string sArr[], int arrLength, char specificChar) {
-    int count;
-    for (int i = 0; i <= arrLength; ++i)
-        for (int j = 0; j <= sArr[i].size(); ++j)
+    int count=0;
+    for (int i = 0; i < arrLength; ++i)
+        for (int j = 0; j < sArr[i].size(); ++j)
             // if the jth char of the string is the specific char
-            if (sArr[i][j] = specificChar)
+            if (sArr[i][j] == specificChar)
                 count++;
     return count;
 }
diff --git a/3.cpp b/3.cpp
index c8732ef..aee6d00 100644
--- a/3.cpp
+++ b/3.cpp
@@ -1,9 +1,10 @@
-#include<stdio.h>
+#include<stdio.h>
 #include<stdlib.h>
+#pragma warning(disable:4996)
 #define MAX_SIZE 200
 int arr[MAX_SIZE];
 
-typedef struct alfa * alfaptr;
+typedef struct alfa* alfaptr;
 
 struct alfa {
 	long long x;
@@ -45,7 +46,7 @@ void search(int x)
 			printf("ERROR2");
 			break;
 		}
-		node = node->next;
+	node = node->next;
 }
 
 void rpop() {//pop last element
@@ -66,9 +67,9 @@ void set()
 int size()
 {
 	alfaptr node = front;
-	int count;
+	int count=0;
 	while (node)
-		count++;node = node->next;
+		count++; node = node->next;
 	return count;
 }
 
@@ -88,7 +89,7 @@ int average()
 {
 
 	alfaptr node = front;
-	int sum = 0, count;
+	int sum = 0, count=0;
 	while (node) {
 		sum += node->x;
 		count++;
diff --git a/4.cpp b/4.cpp
index a9a32f2..95b1838 100644
--- a/4.cpp
+++ b/4.cpp
@@ -2,8 +2,9 @@
 int main()
 {
     float arr[5] = { 12.5, 10.0, 13.5, 90.5, 0.5 };
-    float *ptr1 = &arr[0];
-    float *ptr2 = ptr1 + 3;
+    float* ptr1 = &arr[0];
+    float* ptr2 = ptr1 + 3;
     printf("%f", *ptr2 - *ptr1);
     return 0;
-}
\ No newline at end of file
+}
+//output:78.000000
\ No newline at end of file
diff --git a/5.cpp b/5.cpp
index e9a1737..edf7e9a 100644
--- a/5.cpp
+++ b/5.cpp
@@ -1,10 +1,11 @@
-#include<stdio.h>
+#include<stdio.h>
 int main()
 {
     int arr[] = { 10, 20, 30, 40, 50, 60 };
-    int *ptr1 = arr;
-    int *ptr2 = arr + 5;
+    int* ptr1 = arr;
+    int* ptr2 = arr + 5;
     printf("%d\n", (*ptr2 - *ptr1));
     printf("%c", (char)(*ptr2 - *ptr1));
     return 0;
-}
\ No newline at end of file
+}
+//output:50 2
diff --git a/6.cpp b/6.cpp
index bb721c3..09e07a8 100644
--- a/6.cpp
+++ b/6.cpp
@@ -1,11 +1,12 @@
-#include<stdio.h>
+#include<stdio.h>
 int main()
 {
 	int a;
-	char *x;
-	x = (char *)&a;
+	char* x;
+	x = (char*)&a;
 	a = 512;
 	x[0] = 1;
 	printf("%d\n", a);
 	return 0;
 }
+//output:513
\ No newline at end of file
diff --git a/7.cpp b/7.cpp
index 7b065a0..80f3e24 100644
--- a/7.cpp
+++ b/7.cpp
@@ -2,9 +2,10 @@
 int main()
 {
 	int arr[] = { 1, 2, 3, 4, 5 };
-	int *p = arr;
-	++*p;
+	int* p = arr;
+	++* p;
 	p += 2;
 	printf("%d", *p);
 	return 0;
-}
\ No newline at end of file
+}
+//output:3
\ No newline at end of file
diff --git a/8.cpp b/8.cpp
index 76b870c..efc2780 100644
--- a/8.cpp
+++ b/8.cpp
@@ -1,13 +1,11 @@
-#include<stdio.h>
-const char * f(const char **p) {
+#include<stdio.h>
+const char* f(const char** p) {
 	auto q = (p + sizeof(char))[1];
 	return q;
 }
 int main() {
-	const char * str[] = { "Wish","You","Best",":D" };
+	const char* str[] = { "Wish","You","Best",":D" };
 	printf("%c%c ", *f(str), *(f(str) + 1));
 	printf("%c%c%c%c\n", **str, *(*(str + 1) + 1), *((str + 2)[-1] + 1), **&*(&str[-1] + 1));
-
-
-	
 }
+//output: Be WooW
\ No newline at end of file