debugging and outputs

1.cpp

@@ -2,25 +2,27 @@
 using namespace std;
 
 class container {
-
+protected:
 	int size;
 public:
 	float* p;
-	container(int s) :size(s){}
-	const int& getsize() { return size;}
+	container() { size = 0; }
+	container(int s) :size(s) {}
+	int& getsize() { return size; }
 
 };
 
 class vector :public container {
 
 	int call_num;
 public:
-	explicit vector(int l) :len(l),size(1 * 100){
-		p = new float();
+	explicit vector(int l) :len(l) {
+		size = 1 * 100;
+		p = new float[size];
 	}
 	int len;
-	int& getlen() const {
-		call_num ++;
+	int& getlen()  {
+		call_num++;	//you can not change this object because this function is const
 		return len;
 	}
 	~vector() = default;
@@ -29,12 +31,13 @@ class vector :public container {
 int main() {
 
 	container c1(100);
-	vector v1 = c1;
+	//vector v1 = c1;	you can not put a parent in its child
+	vector v1(100);
 	container& r1 = v1;
 	container c2 = 100;
 	c2.getsize() = 20;
 	cout << c2.getsize();
-	vector v2 = 100;
-	v2.getlen = 40;
+	vector v2(100);	// can not be implicit like this : vector v2 = 100;
+	v2.getlen() = 40;
 	cout << v2.getlen();
 }

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;
 }

3.cpp

@@ -1,9 +1,10 @@
-#include<stdio.h>
+#pragma warning(disable:4996)
+#include<stdio.h>
 #include<stdlib.h>
 #define MAX_SIZE 200
 int arr[MAX_SIZE];
 
-typedef struct alfa * alfaptr;
+typedef struct alfa* alfaptr;
 
 struct alfa {
 	long long x;
@@ -15,19 +16,22 @@ void push(int x)
 	alfaptr node;
 	node = (alfaptr)malloc(sizeof(struct alfa));
 	node->x = x;
-	if (!front)
+	if (front) {
+		alfaptr temp = front;
 		front = node;
+		front->next = front;
+	}
 	else {
-		rear->next = node;
 		rear = node;
+		front = node;
 	}
 }
 
 void pop()
 {
 	alfaptr node;
 	if (!front)
-		printf("ERROR1");
+		printf("ERROR1\n");
 	else
 	{
 		node = front->next;
@@ -38,19 +42,27 @@ void search(int x)
 {
 	alfaptr node = front;
 	int counter = 0;
-	while (node)
+	if(node == NULL) {
+		printf("ERROR2");
+		return;
+	}
+	while (node) {
 		if (node->x == x)
-			printf("%d", counter);
-		else {
-			printf("ERROR2");
-			break;
-		}
+			printf("%d\n", counter);
 		node = node->next;
+	}
 }
 
 void rpop() {//pop last element
 	alfaptr node = front;
-	while (node)
+	if (!node)
+		return;
+	if (!node->next) {
+		free(rear);
+		rear = front;
+		return;
+	}
+	while (node->next->next)
 		node = node->next;
 	free(rear);
 	rear = node;
@@ -59,36 +71,38 @@ void rpop() {//pop last element
 void set()
 {
 	alfaptr node = front;
-	for (int i = 0; i < MAX_SIZE && node; i++, node = node->next)
+	for (int i = 0; (i < MAX_SIZE) && (node != NULL); i++, node = node->next)
 		arr[i] = node->x;
 }
 
 int size()
 {
 	alfaptr node = front;
-	int count;
-	while (node)
-		count++;node = node->next;
+	int count = 0;
+	while (node) {
+		count++; 
+		node = node->next;
+	}
 	return count;
 }
 
 void show()
 {
-	if (!front) {
+	if (front) {
 		for (int i = 0; i < MAX_SIZE; i++)
 			printf("%d ", arr[i]);
 	}
 	else
 	{
-		printf("ERROR3");
+		printf("ERROR3\n");
 	}
 }
 
-int average()
+double average()
 {
 
 	alfaptr node = front;
-	int sum = 0, count;
+	int sum = 0, count = 0;
 	while (node) {
 		sum += node->x;
 		count++;
@@ -127,7 +141,10 @@ void main()
 			show();
 			break;
 		case 7://size
-			printf("%d", size());
+			printf("%d\n", size());
+			break;
+		case 8://average
+			printf("%d\n", average());
 			break;
 		case 10:
 			exit(0);

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;
-}
+}
+//output : 78.000000

5.cpp

@@ -2,9 +2,11 @@
 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;
-}
+}
+//output : 50   //first line
+//output : 2   //second lise

6.cpp

@@ -2,10 +2,11 @@
 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

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;
-}
+}
+//output : 3

8.cpp

@@ -1,13 +1,14 @@
 #include<stdio.h>
-const char * f(const char **p) {
+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