Bài này làm như nào vậy ạ

include <stdio.h>

int main(){

int a, b, c, d;
scanf("%d%d%d%d", &a, &b, &c, &d);
//tao 1 bien chua cac thanh phan vua nhap
int chua[4]={a, b, c, d};
//tao bien neu khong tao dc se hien thi -1
int thoigiancu = -1;
// dat -1 cho de nhan biet neu loi sai
int kqgio = -1;
int kqphut = -1;

for(int i=0; i <= 3; i++){
    for(int j=0; j<=3; j++){
        for(int k=0; k<=3; k++){
            for(int l=0; l<=3; l++){
                if(i!=j && i!=k && i!=l && j!=k && j!=l && k!=l){
                    int gio =(chua[i] *10) + chua[j];
                    int phut =(chua[k] *10) + chua[l];
                    
                    if(gio <24 && phut < 60){
                        int tongphut = (gio * 60) + phut;
                        	if(tongphut > thoigiancu){
                           		 thoigiancu = tongphut;
                           		 kqgio = gio;
                           		 kqphut = phut;
                        }
                    }
                    	
                    
                }
            }
        }
    }
}
        if(thoigiancu == -1){
            printf("%d", thoigiancu);
        }
        else
        {
            printf("%.2d:%.2d", kqgio, kqphut);
        }
        return 0;

}

include <stdio.h>

include <stdlib.h>

include <string.h>

typedef struct SinhVien {

char maSo[11];
char hoTen[41];
float diemTrungBinh;
struct SinhVien *next;

} SinhVien;

SinhVien taoNode(char maSo, char *hoTen, float diemTrungBinh) {

SinhVien *sv = (SinhVien*)malloc(sizeof(SinhVien));
strcpy(sv->maSo, maSo);
strcpy(sv->hoTen, hoTen);
sv->diemTrungBinh = diemTrungBinh;
sv->next = NULL;
return sv;

} void themCuoi(SinhVien **head, SinhVien *sv) {

if (*head == NULL) {
    *head = sv;
} else {
    SinhVien *temp = *head;
    while (temp->next != NULL) {
        temp = temp->next;
    }
    temp->next = sv;
}

}

void xuatDanhSach(SinhVien *head) {

SinhVien *p = head;
while (p != NULL) {
    printf("%s - %s - %.2f\n", p->maSo, p->hoTen, p->diemTrungBinh);
    p = p->next;
}

}

int main() {

SinhVien *head = NULL;
int n;
scanf("%d", &n);

for (int i = 0; i < n; i++) {
    char maSo[11], hoTen[41];
    float diemTrungBinh;
    scanf("%s", maSo);
    scanf(" %[^\n]", hoTen);
    scanf("%f", &diemTrungBinh);
    SinhVien *sv = taoNode(maSo, hoTen, diemTrungBinh);
    themCuoi(&head, sv);
}

xuatDanhSach(head);

return 0;

}

bài b

include <stdio.h>

include <stdlib.h>

include <string.h>

typedef struct SinhVien {

char maSo[11];
char hoTen[41];
float diemTrungBinh;
struct SinhVien *next;

} SinhVien;

SinhVien* taoNode(char maSo[], char hoTen[], float diemTrungBinh) {

SinhVien *sv = (SinhVien*)malloc(sizeof(SinhVien));
strcpy(sv->maSo, maSo);
strcpy(sv->hoTen, hoTen);
sv->diemTrungBinh = diemTrungBinh;
sv->next = NULL;
return sv;

}

void themVaoCuoi(SinhVien **head, SinhVien *sv) {

if (*head == NULL) {
    *head = sv;
} else {
    SinhVien *temp = *head;
    while (temp->next != NULL) {
        temp = temp->next;
    }
    temp->next = sv;
}

}

void locSinhVien(SinhVien *head) {

SinhVien *temp = head;
while (temp != NULL) {
    if (temp->diemTrungBinh > 5) {
        printf("%s - %s - %.2f\n", temp->maSo, temp->hoTen, temp->diemTrungBinh);
    }
    temp = temp->next;
}

}

int main() {

int n;
scanf("%d", &n);
SinhVien *head = NULL;
for (int i = 0; i < n; i++) {
    char maSo[11], hoTen[41];
    float diemTrungBinh;
    scanf("%s", maSo);
    getchar();
    fgets(hoTen, sizeof(hoTen), stdin);
    hoTen[strcspn(hoTen, "\n")] = '\0';
    scanf("%f", &diemTrungBinh);
    SinhVien *sv = taoNode(maSo, hoTen, diemTrungBinh);
    themVaoCuoi(&head, sv);
}
locSinhVien(head);
return 0;

} bài c

include <stdio.h>

include <stdlib.h>

include <string.h>

typedef struct SinhVien {

char maSo[11];
char hoTen[41];
float diemTrungBinh;
struct SinhVien *next;

} SinhVien; SinhVien* taoNode(char maSo[], char hoTen[], float diemTrungBinh) {

SinhVien *sv = (SinhVien*)malloc(sizeof(SinhVien));
strcpy(sv->maSo, maSo);
strcpy(sv->hoTen, hoTen);
sv->diemTrungBinh = diemTrungBinh;
sv->next = NULL;
return sv;

}

void themVaoCuoi(SinhVien **head, SinhVien *sv) {

if (*head == NULL) {
    *head = sv;
} else {
    SinhVien *temp = *head;
    while (temp->next != NULL) {
        temp = temp->next;
    }
    temp->next = sv;
}

}

void timKiemSinhVien(SinhVien *head, char maSo[]) {

SinhVien *temp = head;
while (temp != NULL) {
    if (strcmp(temp->maSo, maSo) == 0) {
        printf("%s - %s - %.2f\n", temp->maSo, temp->hoTen, temp->diemTrungBinh);
        return;
    }
    temp = temp->next;
}
printf("Not Found\n");

}

int main() {

int n;
scanf("%d", &n);
SinhVien *head = NULL;

for (int i = 0; i < n; i++) {
    char maSo[11], hoTen[41];
    float diemTrungBinh;
    scanf("%s", maSo);
    getchar(); // Đọc ký tự xuống dòng thừa
    fgets(hoTen, sizeof(hoTen), stdin);
    hoTen[strcspn(hoTen, "\n")] = '\0';
    scanf("%f", &diemTrungBinh);
    SinhVien *sv = taoNode(maSo, hoTen, diemTrungBinh);
    themVaoCuoi(&head, sv);
}

char maSoTimKiem[11];
scanf("%s", maSoTimKiem);
timKiemSinhVien(head, maSoTimKiem);

return 0;

} bài d

include <stdio.h>

include <stdlib.h>

include <string.h>

typedef struct SinhVien {

char maSo[11];
char hoTen[41];
float diemTrungBinh;
struct SinhVien *next;

} SinhVien;

SinhVien* taoNode(char maSo[], char hoTen[], float diemTrungBinh) {

SinhVien *sv = (SinhVien*)malloc(sizeof(SinhVien));
strcpy(sv->maSo, maSo);
strcpy(sv->hoTen, hoTen);
sv->diemTrungBinh = diemTrungBinh;
sv->next = NULL;
return sv;

}

void themVaoCuoi(SinhVien **head, SinhVien *sv) {

if (*head == NULL) {
    *head = sv;
} else {
    SinhVien *temp = *head;
    while (temp->next != NULL) {
        temp = temp->next;
    }
    temp->next = sv;
}

}

void hienThiDanhSach(SinhVien *head) {

SinhVien *temp = head;
while (temp != NULL) {
    printf("%s - %s - %.2f\n", temp->maSo, temp->hoTen, temp->diemTrungBinh);
    temp = temp->next;
}

}

void sapXepDanhSach(SinhVien **head) {

if (*head == NULL || (*head)->next == NULL) {
    return;
}

SinhVien *i, *j;
for (i = *head; i != NULL; i = i->next) {
    for (j = i->next; j != NULL; j = j->next) {
        if (i->diemTrungBinh < j->diemTrungBinh) {
            char tempMaSo[11], tempHoTen[41];
            float tempDiem;

            strcpy(tempMaSo, i->maSo);
            strcpy(tempHoTen, i->hoTen);
            tempDiem = i->diemTrungBinh;

            strcpy(i->maSo, j->maSo);
            strcpy(i->hoTen, j->hoTen);
            i->diemTrungBinh = j->diemTrungBinh;strcpy(j->maSo, tempMaSo);
            strcpy(j->hoTen, tempHoTen);
            j->diemTrungBinh = tempDiem;
        }
    }
}

}

int main() {

int n;
scanf("%d", &n);
SinhVien *head = NULL;

for (int i = 0; i < n; i++) {
    char maSo[11], hoTen[41];
    float diemTrungBinh;
    scanf("%s", maSo);
    getchar(); // Đọc ký tự xuống dòng thừa
    fgets(hoTen, sizeof(hoTen), stdin);
    hoTen[strcspn(hoTen, "\n")] = '\0'; 
    scanf("%f", &diemTrungBinh);

    SinhVien *sv = taoNode(maSo, hoTen, diemTrungBinh);
    themVaoCuoi(&head, sv);
}
sapXepDanhSach(&head);
hienThiDanhSach(head);

return 0;

} bài e

include

include

include

include

using namespace std;

// Sinh viên khai báo thu vi?n t?i dây struct Node {

int data;
Node* left;
Node* right;
int height;

};

// Sinh viên khai báo các bi?n toàn c?c t?i dây (n?u có)

// Sinh viên khai báo hàm t?i dây int height(Node node); int getBalance(Node node); Node rightRotate(Node y); Node leftRotate(Node x); Node insert(Node node, int data); bool search(Node node, int key); void printInOrder(Node node); Node inputAVL(Node root); Node createRandomAVL(int n); void countIntermediateNodes(Node node, int &count); Node deletePerfectSquare(Node root); Node findParent(Node root, int x); void printSubtree(Node* root, int x);

// Sinh viên vi?t câu l?nh trong hàm main int main() {

Node* root = NULL;
int choice;

while (true) {
    cout << "\nMenu:\n";
    cout << "1. Nhap cay AVL\n";
    cout << "2. Xuat cay AVL\n";
    cout << "3. Tao ngau nhien cay AVL\n";
    cout << "4. Tim kiem x co ton tai trong cay AVL hay khong?\n";
    cout << "5. Dem so nut trung gian cua cay AVL\n";
    cout << "6. Xoa node co gia tri la so chinh phuong cua cay AVL\n";
    cout << "7. Input so nguyen x. Xuat ra man hinh\n";
    cout << "0. Thoat\n";
    cout << "Chon: ";
    cin >> choice;

    switch (choice) {
        case 1:
            root = inputAVL(root);
            break;
        case 2:
            cout << "Cay AVL (In-order): ";
            printInOrder(root);
            break;
        case 3:
            cout << "Nhap so node n: ";
            int n;
            cin >> n;
            root = createRandomAVL(n);
            cout << "Cay AVL ngau nhien da duoc tao.\n";
            break;
        case 4:
            {
                int x;
                cout << "Nhap gia tri x: ";
                cin >> x;
                if (search(root, x)) {
                    cout << "Gia tri " << x << " ton tai trong cay AVL.\n";
                } else {
                    cout << "Gia tri " << x << " khong ton tai trong cay AVL.\n";
                }
            }
            break;
        case 5:
            {
                int count = 0;
                countIntermediateNodes(root, count);
                cout << "So nut trung gian trong cay AVL: " << count << endl;
            }
            break;
        case 6:
            root = deletePerfectSquare(root);
            break;
        case 7:
            {
                int x;
                cout << "Nhap gia tri x: ";
                cin >> x;
                Node* parent = findParent(root, x);
                if (parent != NULL) {
                    cout << "Gia tri cha cua node " << x << ": " << parent->data << endl;
                } else {
                    cout << "Khong tim thay cha cua node " << x << endl;
                }
                printSubtree(root, x);
            }
            break;
        case 0:
            cout << "Thoat chuong trinh.\n";
            return 0;
        default:
            cout << "Chon sai, vui long chon lai.\n";
    }
}

return 0;

}

// Sinh viên vi?t n?i dung hàm tuong ?ng sau dòng này

int height(Node* node) {

if (node == NULL) {
    return 0;
}
return node->height;

}

int getBalance(Node* node) {

if (node == NULL) {
    return 0;
}
return height(node->left) - height(node->right);

}

Node rightRotate(Node y) {

Node* x = y->left;
Node* T2 = x->right;

x->right = y;
y->left = T2;

y->height = max(height(y->left), height(y->right)) + 1;
x->height = max(height(x->left), height(x->right)) + 1;

return x;

}

Node leftRotate(Node x) {

Node* y = x->right;
Node* T2 = y->left;

y->left = x;
x->right = T2;

x->height = max(height(x->left), height(x->right)) + 1;
y->height = max(height(y->left), height(y->right)) + 1;

return y;

}

Node insert(Node node, int data) {

if (node == NULL) {
    Node* newNode = new Node();
    newNode->data = data;
    newNode->left = newNode->right = NULL;
    newNode->height = 1;
    return newNode;
}

if (data < node->data) {
    node->left = insert(node->left, data);
} else if (data > node->data) {
    node->right = insert(node->right, data);
} else {
    return node;
}

node->height = max(height(node->left), height(node->right)) + 1;

int balance = getBalance(node);

if (balance > 1 && data < node->left->data) {
    return rightRotate(node);
}
if (balance < -1 && data > node->right->data) {
    return leftRotate(node);
}
if (balance > 1 && data > node->left->data) {
    node->left = leftRotate(node->left);
    return rightRotate(node);
}
if (balance < -1 && data < node->right->data) {
    node->right = rightRotate(node->right);
    return leftRotate(node);
}

return node;

}

bool search(Node* node, int key) {

if (node == NULL) {
    return false;
}
if (node->data == key) {
    return true;
} else if (key < node->data) {
    return search(node->left, key);
} else {
    return search(node->right, key);
}

}

void printInOrder(Node* node) {

if (node == NULL) return;
printInOrder(node->left);
cout << node->data << " ";
printInOrder(node->right);

}

Node inputAVL(Node root) {

int n, value;
cout << "Nhap so luong nut: ";
cin >> n;
cout << "Nhap gia tri cua cac nut:\n";
for (int i = 0; i < n; i++) {
    cin >> value;
    root = insert(root, value);
}
return root;

}

Node* createRandomAVL(int n) {

Node* root = NULL;
for (int i = 0; i < n; i++) {
    int value = rand() % 100;
    root = insert(root, value);
}
return root;

}

void countIntermediateNodes(Node* node, int &count) {

if (node == NULL) return;

if (node->left != NULL && node->right != NULL) {
    count++;
}

countIntermediateNodes(node->left, count);
countIntermediateNodes(node->right, count);

}

Node deletePerfectSquare(Node root) {

if (root == NULL) return NULL;

if (root->data == (int)sqrt(root->data) * (int)sqrt(root->data)) {
    return NULL; // Xóa node chính phuong
}

root->left = deletePerfectSquare(root->left);
root->right = deletePerfectSquare(root->right);

return root;

}

Node findParent(Node root, int x) {

if (root == NULL || (root->left == NULL && root->right == NULL)) return NULL;

if ((root->left != NULL && root->left->data == x) || (root->right != NULL && root->right->data == x)) {
    return root;
}

Node* leftSearch = findParent(root->left, x);
if (leftSearch != NULL) return leftSearch;

return findParent(root->right, x);

}

void printSubtree(Node* root, int x) {

if (root == NULL) return;

if (root->data == x) {
    cout << "Cay con cua node: " << x<<endl;
    if (root->left != NULL) {
        cout << "Left child: " << root->left->data << endl;
        printInOrder(root->left);
    }
    if (root->right != NULL) {
        cout << "Right child: " << root->right->data << endl;
        printInOrder(root->right);
    }
}

printSubtree(root->left, x);
printSubtree(root->right, x);

}

bài này code như thế nào ạ, em cảm ơn