there was 8 error that was fixed in this

1.cpp

@@ -2,39 +2,40 @@
 using namespace std;
 
 class container {
-
-	int size;
+    int size;
 public:
-	float* p;
-	container(int s) :size(s){}
-	const int& getsize() { return size;}
-
+    container(int s) : size(s) {}
+    int& getsize() { return size; } // Return non-constant reference
 };
 
-class vector :public container {
-
-	int call_num;
+class MyVector : public container {
+    int call_num;
+    int len;
 public:
-	explicit vector(int l) :len(l),size(1 * 100){
-		p = new float();
-	}
-	int len;
-	int& getlen() const {
-		call_num ++;
-		return len;
-	}
-	~vector() = default;
+    explicit MyVector(int l) : container(1 * 100), len(l), call_num(0) {
+        p = new float();
+    }
+
+    int& getlen() {
+        call_num++;
+        return len;
+    }
+
+    ~MyVector() = default;
+    float* p; 
 };
 
 int main() {
+    container c1(100);
+    MyVector v1(100); 
+    container& r1 = v1;
+    container c2(100);
+    c2.getsize() = 20; 
+    cout << c2.getsize() << endl;
+
+    MyVector v2(100); 
+    v2.getlen() = 40; 
+    cout << v2.getlen() << endl;
 
-	container c1(100);
-	vector v1 = c1;
-	container& r1 = v1;
-	container c2 = 100;
-	c2.getsize() = 20;
-	cout << c2.getsize();
-	vector v2 = 100;
-	v2.getlen = 40;
-	cout << v2.getlen();
-}
+    return 0;
+}

2.cpp

@@ -3,14 +3,15 @@
 
 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)
-            // if the jth char of the string is the specific char
-            if (sArr[i][j] = specificChar)
+    int count = 0; 
+    for (int i = 0; i < arrLength; ++i) {
+        for (int j = 0; j < sArr[i].size(); ++j) {
+            if (sArr[i][j] == specificChar) {
                 count++;
+            }
+        }
+    }
     return count;
 }
 
@@ -22,6 +23,7 @@ int main() {
             "class"
     };
     char findIt;
-    cin >> findIt;
+    cin >> findIt; 
     cout << countAllSpecificChars(sArr, 4, findIt);
-}
+    return 0;
+}

3.cpp

@@ -1,136 +1,160 @@
-#include<stdio.h>
-#include<stdlib.h>
+#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;
-	alfaptr next;
+    long long x;
+    alfaptr next;
 };
+
 alfaptr rear = NULL, front = NULL;
-void push(int x)
-{
-	alfaptr node;
-	node = (alfaptr)malloc(sizeof(struct alfa));
-	node->x = x;
-	if (!front)
-		front = node;
-	else {
-		rear->next = node;
-		rear = node;
-	}
+
+void push(int x) {
+    alfaptr node;
+    node = (alfaptr)malloc(sizeof(struct alfa));
+    node->x = x;
+    node->next = NULL; // Initialize next pointer to NULL
+
+    if (!front)
+        front = node;
+    else {
+        rear->next = node;
+    }
+    rear = node; // Update rear pointer
 }
 
-void pop()
-{
-	alfaptr node;
-	if (!front)
-		printf("ERROR1");
-	else
-	{
-		node = front->next;
-		front = node;
-	}
+void pop() {
+    if (!front)
+        printf("ERROR1\n");
+    else {
+        alfaptr node = front;
+        front = front->next;
+        free(node);
+    }
 }
-void search(int x)
-{
-	alfaptr node = front;
-	int counter = 0;
-	while (node)
-		if (node->x == x)
-			printf("%d", counter);
-		else {
-			printf("ERROR2");
-			break;
-		}
-		node = node->next;
+
+void search(int x) {
+    alfaptr node = front;
+    int counter = 0;
+    while (node) {
+        if (node->x == x) {
+            printf("%d\n", counter);
+            return;
+        }
+        node = node->next;
+        counter++;
+    }
+    printf("ERROR2\n");
 }
 
-void rpop() {//pop last element
-	alfaptr node = front;
-	while (node)
-		node = node->next;
-	free(rear);
-	rear = node;
+void rpop() { // pop last element
+    alfaptr node = front;
+    alfaptr prev = NULL;
+
+    if (!front) {
+        printf("ERROR1\n");
+        return;
+    }
+
+    while (node->next) {
+        prev = node;
+        node = node->next;
+    }
+
+    if (prev)
+        prev->next = NULL;
+    else
+        front = NULL;
+
+    rear = prev; // Update rear pointer
+
+    free(node);
 }
 
-void set()
-{
-	alfaptr node = front;
-	for (int i = 0; i < MAX_SIZE && node; i++, node = node->next)
-		arr[i] = node->x;
+void set() {
+    alfaptr node = front;
+    int i = 0;
+
+    while (i < MAX_SIZE && node) {
+        arr[i] = node->x;
+        node = node->next;
+        i++;
+    }
 }
 
-int size()
-{
-	alfaptr node = front;
-	int count;
-	while (node)
-		count++;node = node->next;
-	return count;
+int size() {
+    alfaptr node = front;
+    int count = 0;
+
+    while (node) {
+        count++;
+        node = node->next;
+    }
+    return count;
 }
 
-void show()
-{
-	if (!front) {
-		for (int i = 0; i < MAX_SIZE; i++)
-			printf("%d ", arr[i]);
-	}
-	else
-	{
-		printf("ERROR3");
-	}
+void show() {
+    if (!front) {
+        for (int i = 0; i < MAX_SIZE; i++)
+            printf("%d ", arr[i]);
+    } else {
+        printf("ERROR3\n");
+    }
 }
 
-int average()
-{
-
-	alfaptr node = front;
-	int sum = 0, count;
-	while (node) {
-		sum += node->x;
-		count++;
-		node = node->next;
-	}
-	return sum / count;
+int average() {
+    alfaptr node = front;
+    int sum = 0, count = 0;
+
+    while (node) {
+        sum += node->x;
+        count++;
+        node = node->next;
+    }
+
+    return count > 0 ? sum / count : 0; // Check for division by zero
 }
 
-void main()
-{
-	int cmd;
-	long long int x;
-	while (true)
-	{
-		scanf("%d", &cmd);
-		switch (cmd)
-		{
-		case 1://push
-			scanf("%lld", &x);
-			push(x);
-			break;
-		case 2://pop
-			pop();
-			break;
-		case 3://rpop
-			rpop();
-			break;
-		case 4://search
-			scanf("%lld", &x);
-			search(x);
-			break;
-		case 5://set
-			set();
-			break;
-		case 6://show
-			show();
-			break;
-		case 7://size
-			printf("%d", size());
-			break;
-		case 10:
-			exit(0);
-		}
-	}
-}
+int main() {
+    int cmd;
+    long long int x;
+
+    while (1) {
+        scanf("%d", &cmd);
+
+        switch (cmd) {
+            case 1: // push
+                scanf("%lld", &x);
+                push(x);
+                break;
+            case 2: // pop
+                pop();
+                break;
+            case 3: // rpop
+                rpop();
+                break;
+            case 4: // search
+                scanf("%lld", &x);
+                search(x);
+                break;
+            case 5: // set
+                set();
+                break;
+            case 6: // show
+                show();
+                break;
+            case 7: // size
+                printf("%d\n", size());
+                break;
+            case 10:
+                exit(0);
+        }
+    }
+
+    return 0;
+}